[ TUT ] MATH - CALCULATOR TECHNIQUEs

[roxette]

thank you sir! very helpful

 

[rapz94]

UUUUUUPPPPP ... gudluck sa mga kakatake lang ngayung april..

 

[tomasyap]

Re: [tut] math - calculator technique

dito TS malaking tulong ito sa akin

 

[Unleash126]

Re: Session 2 Part 1

SESSION 2 PART 1​

1. Subtract http://latex.codecogs.com/png.latex?\small \fn_cm 60^{\circ}10"-27^{\circ}34'52"
A. http://latex.codecogs.com/png.latex?\small \fn_cm 32^{\circ}25'18"
B. http://latex.codecogs.com/png.latex?\small \fn_cm 32^{\circ}35'8"
C. http://latex.codecogs.com/png.latex?\small \fn_cm 32^{\circ}35'18"
D. http://latex.codecogs.com/png.latex?\small \fn_cm 32^{\circ}25'8"

Siguro naman kayang kaya niyo na ito..:D

2. During a rain, 2mm of water fell. Find how many gallons of water fell on a level 10 acre park.
A. 21,381
B. 25,381
C. 27,381
D. 30,381

Conversion only..
V=10 acre (convert acre to m^2)SHIFT>8(for CONV)>11(for acre>m^2)..It will give an answer 40468.56..
Then multiply it to .002 m(given in the problem) and it will display 80.93712 in m^3..
Convert this to Liters..1 m^3 = 1000L..And it will display 80937.12 in L..
Finally convert this to gal..Press CONV#14 L>gal(US)..
And you will get the answer in gal..

3. The function http://latex.codecogs.com/png.latex?\small \fn_cm f(x)=\frac{(x^{2}-4)}{(x^{3}-2x^{2}-3x+10)} is discontinous at x=?
A. 2
B. -2
C. either a or b
D. neither a nor b

Pag sinabing discontinous, mageerror siya sa value na isusubstitute mo or yung tinatawag na MATH ERROR..Pag may lumalabas parin na value positive or negative or even zero, continous parin yun..dapat mageerror siya..gets?..

Set the calculator to COMP MODE..
type na equation as it is..press the CALC function and substitute the numbers in the choices and find which one will get an error..The one error is the answer..

Alternative solution..we use the TABLE function..MODE 7..
Type the equation as it is and press =
START? (your number depends on the choices..we start from the lowest which is -2..So enter -2 then press =
END? (the largest in the choices)..So enter 2 and press =
STEP? (The variation in the choices)..Important po ito..kailangan madaanan nung function yung mga choices..In this case 2 and -2..So enter 2 and press =

Kung saan may error yun na yun..

4. Find the possible factors of http://latex.codecogs.com/png.latex?\small \fn_cm 4x^{5}-4x^{4}+25x^{3}-30x^{2}-99x+54.
A. (x-2)
B. (2x-1)
C. (2x+3)
D. all of the above

Para masabing factor siya, kailangan ang y=0 pag isusubstitute natin yung root of x..
We use CALC function..Set the calculator to MODE 1..
Type the equation as it is and press CALC..Get the root of the choices and substitute..
X? enter 2 if y=0, then possible root siya..Try the next one..
X? enter 1/2, if y=0, then possible root siya..Try the last one..
X? enter -3/2 if y=0, then possible root siya..

Therefore you know the answer..

5. Determine the area of the triangle bounded by the straight lines x+2y-7=0, 3x-4y-1=0, and 2x-y+6=0..
A. 10 sq.units
B. 15 sq.units
C. 20 sq.units
D. 25 sq.units

First get the point of intersection..use the EQN function..MODE 5>1
For the first two equation, type:
1 2 7
3 -4 1
then press = =..Therefore the point of intersection of this is x=3, and y=2..
Then try the next equation..
3 -4 1
2 -1 -6
Then press = =......x=-5, and y=-4
try the last combination of equation..
1 2 7
2 -1 -6
Then press = =......x=-1, and y=4
Then we use the determinant function to get the area of the triangle..
Set the calculator to MATRIX..MODE 6 and press AC..
What important in this is kailangan natin madaan yung DIM or dimension ng matrix..So press SHIFT>4>1>1>1 and enter
3 2 1
-5 -4 1
-1 4 1
then press AC..
To get the determinant press SHIFT>7(det)>SHIFT>4>3(since we enter our data in MatA..Then press =..
Remember the area of a triangle given the vertices is 0.5 times the determinant..Therefore multiply it to 0.5 and get its Abs value..
Then you will get the final answer..

6. Find the center of the circle that is circumscribed about the triangle whose vertices are (-3,1), (3,1) and (5,3)
A. (-3,9)
B. (3,-9)
C. (-3,-9)
D. (3,9)

Substitute x and y in the general equation of circle.. [url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20x^{2}+y^{2}+Dx+Ey+F=0[/url]
In the first point you will get the equation -3D-E+F=-10
The second point will give you 3D+E+F=-10
The third point will give you 5D+3E+F=-34..

Therefore we have 3 equations, 3 unknown..
Use the EQN 2 and enter
-3 -1 1 -10
3 1 1 -10
5 3 1 -34
And you will get D=6, E=-18, and F=-10
And write it in the general form..
[url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20x^{2}+y^{2}+6x-18y-10=0[/url]

Ito ang shortcut para makuha ang center..
CENTER OF CIRCLE, ELLIPSE or PARABOLA:
(h)
[url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20x=-\frac{Cx}{2Cx^{2}}[/url]

(k)
[url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20y=-\frac{Cy}{2Cy^{2}}[/url]

Therefore our center (h,k) is at (-3,9)..

7. Find the value of y of the parabola whose axis is vertical and passes through (-1,0), (5,0), (1,8) and (4,y)
A. -5
B. 5
C. -6
D. 6

We use STAT 3( for parabola) in this case..
In the x column enter -1,5 and 1..
In the y column enter 0,0, and 8 then press AC

Find the value of y when x = 4..
therefore 4(y-hat) or [url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%204\widehat{y}[/url]

And you will get the answer..

8. Find the sum of an A.P.: 2,5,8..............where n=25..
A. 900
B. 925
C. 950
D. 975

Use STAT 2(for A.P.)
In the x column enter 1,2
In the y column enter 2,5 then press AC..
Use the SUMMATION FUNCTION..

[INDENT][url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20\sum%20(x\widehat{y},1,25)[/url][/INDENT]

And you will get the answer..

9. Find the sum of a G.P.: 2,3,4.5,.................where n=10.
A. 226.66
B. 235.42
C. 242.52
D. 251.84

Same method with #9 BUT use STAT 6(for G.P.)
Then use the SUMMATION function to get the sum..
And you will get the answer..

10. In how many ways can a picture be painted by using three(3) or more of the seven(7) different colors?.
A. 80
B. 99
C. 105
D. 120

Set the calculator to COMP MODE..
We use the COMBINATION function..It will be found by pressing SHIFT > ÷ ( nCr )
And type the equation just like this:

[INDENT][url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20_{7}\textrm{C}_{3}+_{7}\textrm{C}_{4}+_{7}\textrm{C}_{5}+_{7}\textrm{C}_{6}+_{7}\textrm{C}_{7}[/url][/INDENT]

And you will get the answer..

Di ko ma gets kung pano yung ginawa sa number 6. yung sa shortcut kung pano makuha CENTER ng CIRCLE

 

[ThomasM15]

Re: [tut] math - calculator technique

pa bm ts! thanks!!

 

[BLGprincess]

Thank you po sa thread na to .. malaking tulong pu talaga!
BS CpE preparing for Math Comprehensive Exam. *waves*

 

[tomasyap]

Re: [tut] math - calculator technique

for sharing

 

[totenpot07]

hi po.. baka po may mga review materials pa po kayo jan.. salamat po!

 

[gravityaxe]

Re: [tut] math - calculator technique

Pa boss.............

 

[lelouchlawliet]

http://latex.codecogs.com/gif.latex?2^x + 4^x = 8^x

 

[kabayanhustler]

Re: Session 2 Part 1

SESSION 2 PART 1​

1. Subtract http://latex.codecogs.com/png.latex?\small \fn_cm 60^{\circ}10"-27^{\circ}34'52"
A. http://latex.codecogs.com/png.latex?\small \fn_cm 32^{\circ}25'18"
B. http://latex.codecogs.com/png.latex?\small \fn_cm 32^{\circ}35'8"
C. http://latex.codecogs.com/png.latex?\small \fn_cm 32^{\circ}35'18"
D. http://latex.codecogs.com/png.latex?\small \fn_cm 32^{\circ}25'8"

Siguro naman kayang kaya niyo na ito..:D

2. During a rain, 2mm of water fell. Find how many gallons of water fell on a level 10 acre park.
A. 21,381
B. 25,381
C. 27,381
D. 30,381

Conversion only..
V=10 acre (convert acre to m^2)SHIFT>8(for CONV)>11(for acre>m^2)..It will give an answer 40468.56..
Then multiply it to .002 m(given in the problem) and it will display 80.93712 in m^3..
Convert this to Liters..1 m^3 = 1000L..And it will display 80937.12 in L..
Finally convert this to gal..Press CONV#14 L>gal(US)..
And you will get the answer in gal..

3. The function http://latex.codecogs.com/png.latex?\small \fn_cm f(x)=\frac{(x^{2}-4)}{(x^{3}-2x^{2}-3x+10)} is discontinous at x=?
A. 2
B. -2
C. either a or b
D. neither a nor b

Pag sinabing discontinous, mageerror siya sa value na isusubstitute mo or yung tinatawag na MATH ERROR..Pag may lumalabas parin na value positive or negative or even zero, continous parin yun..dapat mageerror siya..gets?..

Set the calculator to COMP MODE..
type na equation as it is..press the CALC function and substitute the numbers in the choices and find which one will get an error..The one error is the answer..

Alternative solution..we use the TABLE function..MODE 7..
Type the equation as it is and press =
START? (your number depends on the choices..we start from the lowest which is -2..So enter -2 then press =
END? (the largest in the choices)..So enter 2 and press =
STEP? (The variation in the choices)..Important po ito..kailangan madaanan nung function yung mga choices..In this case 2 and -2..So enter 2 and press =

Kung saan may error yun na yun..

4. Find the possible factors of http://latex.codecogs.com/png.latex?\small \fn_cm 4x^{5}-4x^{4}+25x^{3}-30x^{2}-99x+54.
A. (x-2)
B. (2x-1)
C. (2x+3)
D. all of the above

Para masabing factor siya, kailangan ang y=0 pag isusubstitute natin yung root of x..
We use CALC function..Set the calculator to MODE 1..
Type the equation as it is and press CALC..Get the root of the choices and substitute..
X? enter 2 if y=0, then possible root siya..Try the next one..
X? enter 1/2, if y=0, then possible root siya..Try the last one..
X? enter -3/2 if y=0, then possible root siya..

Therefore you know the answer..

5. Determine the area of the triangle bounded by the straight lines x+2y-7=0, 3x-4y-1=0, and 2x-y+6=0..
A. 10 sq.units
B. 15 sq.units
C. 20 sq.units
D. 25 sq.units

First get the point of intersection..use the EQN function..MODE 5>1
For the first two equation, type:
1 2 7
3 -4 1
then press = =..Therefore the point of intersection of this is x=3, and y=2..
Then try the next equation..
3 -4 1
2 -1 -6
Then press = =......x=-5, and y=-4
try the last combination of equation..
1 2 7
2 -1 -6
Then press = =......x=-1, and y=4
Then we use the determinant function to get the area of the triangle..
Set the calculator to MATRIX..MODE 6 and press AC..
What important in this is kailangan natin madaan yung DIM or dimension ng matrix..So press SHIFT>4>1>1>1 and enter
3 2 1
-5 -4 1
-1 4 1
then press AC..
To get the determinant press SHIFT>7(det)>SHIFT>4>3(since we enter our data in MatA..Then press =..
Remember the area of a triangle given the vertices is 0.5 times the determinant..Therefore multiply it to 0.5 and get its Abs value..
Then you will get the final answer..

6. Find the center of the circle that is circumscribed about the triangle whose vertices are (-3,1), (3,1) and (5,3)
A. (-3,9)
B. (3,-9)
C. (-3,-9)
D. (3,9)

Substitute x and y in the general equation of circle.. [url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20x^{2}+y^{2}+Dx+Ey+F=0[/url]
In the first point you will get the equation -3D-E+F=-10
The second point will give you 3D+E+F=-10
The third point will give you 5D+3E+F=-34..

Therefore we have 3 equations, 3 unknown..
Use the EQN 2 and enter
-3 -1 1 -10
3 1 1 -10
5 3 1 -34
And you will get D=6, E=-18, and F=-10
And write it in the general form..
[url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20x^{2}+y^{2}+6x-18y-10=0[/url]

Ito ang shortcut para makuha ang center..
CENTER OF CIRCLE, ELLIPSE or PARABOLA:
[COLOR="#00FF00"](h)
[url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20x=-\frac{Cx}{2Cx^{2}}[/url]

(k)
[url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20y=-\frac{Cy}{2Cy^{2}}[/url][/COLOR]

Therefore our center (h,k) is at (-3,9)..

7. Find the value of y of the parabola whose axis is vertical and passes through (-1,0), (5,0), (1,8) and (4,y)
A. -5
B. 5
C. -6
D. 6

We use STAT 3( for parabola) in this case..
In the x column enter -1,5 and 1..
In the y column enter 0,0, and 8 then press AC

Find the value of y when x = 4..
therefore 4(y-hat) or [url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%204\widehat{y}[/url]

And you will get the answer..

8. Find the sum of an A.P.: 2,5,8..............where n=25..
A. 900
B. 925
C. 950
D. 975

Use STAT 2(for A.P.)
In the x column enter 1,2
In the y column enter 2,5 then press AC..
Use the SUMMATION FUNCTION..

[INDENT][url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20\sum%20(x\widehat{y},1,25)[/url][/INDENT]

And you will get the answer..

9. Find the sum of a G.P.: 2,3,4.5,.................where n=10.
A. 226.66
B. 235.42
C. 242.52
D. 251.84

Same method with #9 BUT use STAT 6(for G.P.)
Then use the SUMMATION function to get the sum..
And you will get the answer..

10. In how many ways can a picture be painted by using three(3) or more of the seven(7) different colors?.
A. 80
B. 99
C. 105
D. 120

Set the calculator to COMP MODE..
We use the COMBINATION function..It will be found by pressing SHIFT > ÷ ( nCr )
And type the equation just like this:

[INDENT][url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20_{7}\textrm{C}_{3}+_{7}\textrm{C}_{4}+_{7}\textrm{C}_{5}+_{7}\textrm{C}_{6}+_{7}\textrm{C}_{7}[/url][/INDENT]

And you will get the answer..

For question number 6, I'm not sure I understand what to do of finding h and k using the shortcut formula, I'm so dense kindly help pls. Thanks a bunch and great thread!

EDIT: nevermind nagets ko na C stands for coefficient of x and coefficient of x squared. For those wondering what C stands for in Problem 6. Thanks!

 

[kevinthegreat]

halimaw nga talga dyan si sir romeo tolentino. usefull tlga sia pati mga strength of materials at mechanics kaya. keep it up pare.

 

[chynard27]

Re: Additional Exercises - PART 2

Additional Exercises - PART 2​

11. Evaluate http://latex.codecogs.com/png.latex?\small \fn_cm \sum_{k=1}^{30}k(k+1)
A. 9920
B. 2920
C. 9200
D. 2290

Set the calculator to computation mode: MODE>1
Input the equation as is but replace k with X..
Then press =..
And you will get the answer..

12. Find x, if http://latex.codecogs.com/png.latex?\small \fn_cm 2\log_{x}3+\log_{x}2=2+\log_{x}6
A. http://latex.codecogs.com/png.latex?\small \fn_cm \sqrt{2}
B. http://latex.codecogs.com/png.latex?\small \fn_cm \sqrt{3}
C. http://latex.codecogs.com/png.latex?\small \fn_cm \sqrt{5}
D. http://latex.codecogs.com/png.latex?\small \fn_cm \sqrt{7}

Set calculator to computation mode..
Type the equation as is..Use the "SOLVE" function and press =..
And you will get the answer..

13. Factor http://latex.codecogs.com/png.latex?\small \fn_cm 8x^{3}-36x^{2}+54x-27
A. http://latex.codecogs.com/png.latex?\small \fn_cm (2x-3)^{3}
B. http://latex.codecogs.com/png.latex?\small \fn_cm -(3x-2)^{3}
C. http://latex.codecogs.com/png.latex?\small \fn_cm (2x+3)^{3}
D. http://latex.codecogs.com/png.latex?\small \fn_cm -(3x+2)^{3}

First, type the equation and assign an arbitrary constant to substitute to x and use the CALC function..
for example X=8
The calculator will display "2197"..
Second, substitute 8 to the choices and find which one will be equal to "2197"..
Start with the first choice until you get the value of "2197"..
What we do as well in the previous examples like this is called "REVERSE ENGINEERING"..

14. Find the 15th term in the arithmetic sequence: 1,3,5,7 . . .
A. 25
B. 27
C. 29
D. 31

1. Set the calculator to STAT mode..MODE 3>2
2: A+BX is for Arithmetic Progression( A.P.)..
May makikita kayo X and Y column..And X column natin ay ang nth term while sa Y column natin ay ang A.P..
2. Input sa X column ang 1,2,3(1st term,2nd term, 3rd term)..Sa Y column naman, iinput ang 1,3,5 (kahit 3 number lang, kahit wag na yung 7)..
Which mean the 1st term of the A.P. is 1, 2nd term is 3 and 3rd term is 7..
3. After niyo mainput, press AC(don't worry hindi mabubura ang data niyo)
Sa problem ang hinahanap ay ang pang 15th term..anu ba ang value ng ika-15th term?..meaning ang hinahanap ang value sa Y column..gets?..
4. Therefore, type 15Y-hat..
Ang Y-hat ay makikita when you press SHIFT>1(STAT)>7(Reg)>5(Y-hat)..while ang X-hat ay makikita when you press SHIFT>1(STAT)>7(Reg)>4(X-hat)..take note of this dahil gagamitin natin ito in the next problems..
5. Then press =..
And you will get the answer..
Kung may tanong kayo dito at di niyo makuha pakipost na lang..

15. Find the 12th term in the geometric series: 3, 9, 27 . . .
A. 59,049
B. 177,147
C. 531,141
D. 1,594,323

1. Set the calculator to STAT mode..MODE 3>5 or MODE3>6 (it's the same for Geometric Progression, G.P.)

May makikita kayo X and Y column..And X column natin ay ang nth term while sa Y column natin ay ang G.P..
2. Input sa X column ang 1,2,3(1st term,2nd term, 3rd term)..Sa Y column naman, iinput ang 3,9,27..
Which mean the 1st term of the G.P. is 3, 2nd term is 9 and 3rd term is 27..
3. After niyo mainput, press AC(don't worry hindi mabubura ang data niyo)
Sa problem ang hinahanap ay ang pang 12th term..anu ba ang value ng ika-12th term?..meaning ang hinahanap ang value sa Y column..gets?..
4. Therefore, type 12Y-hat..
5. Then press =..
And you will get the answer..
Kung may tanong kayo dito at di niyo makuha pakipost na lang..

16. What is the sum of the first 20 terms of the sequence: 1, 3, 5, 7...
A. 361
B. 391
C. 400
D. 441

1. Set the calculator to STAT mode: MODE 3>2 (since it is A.P.)
2. In the X column, input 1,2,3..In the Y column, input 1,3,5..
3. After you input the data, press AC..Don't worry your data will not be deleted (unless you change your mode)
4. Press SHIFT>LOG(found below the ON KEY)..we will use the SUMMATION function..(SUMMATION symbol is like E)
5. Press ALPHA>)(for X)>SHIFT>1>7>5(for Y-hat)>SHIFT>)(for comma)>1>SHIFT>)(for comma)>21>)
6. You will noticed that our summation is from 1 to 21..Why 21 and not 20?..Because we start our progression in 1..If we start the progression from 0, then that's the time we use 0 to 20..

And it will be like this..walang Y-hat na symbol e..
[INDENT][url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20\sum%20(X(Y-Hat),1,21)[/url][/INDENT]

And you will get the answer..

17. What is the sum of the infinite series: 1, -1/5, 1/25, . . .
A. 5/6
B. 4/5
C. 5/7
D. 6/7

1. Set the calculator to Computation Mode..MODE>1
Since this is an infinite series, with a common ratio of less than 1, then the sum is a finite number..(NOTE: For an infinite series with  a common ratio of greater than 1, the sum is infinite)..
2. Input the equation under SUMMATION function and get the sum from 0 to a large value, say, 50.So it will be like this..Then press =

[INDENT][url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20\sum_{x=0}^{50}((-\frac{1}{5})^{x})[/url][/INDENT]

18. What is the sum of 6+9+12+. . .+171?
A. 4956
B. 4389
C. 5198
D. 5462

1. Set the Calculator to STAT mode..MODE3>2 (I hope you already know why MODE 3 2)
2. In the X column, input 1,2,3....In the Y column, input 6,9,12 then press AC..
3. We should get the sum but we don't know how many term does it have..So let's determine how many terms it has..Earlier in this tutorial I said X is for nth term and Y is for progression..Therefore, our code is 171X-hat..Since 171 is our last term..And the calculator will display "56"
4. now use the SUMMATION function like in number 26 but this time, its 1,56..

[INDENT][url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20\sum%20(x(Y-Hat)1,56)[/url][/INDENT]

19. What is the 6th term of the infinite series: 1, -1/5, 1/25, ...
A. 1/3125
B. 1/15625
C. -1/3125
D. -1/15625

1. Set the calculator to Computation mode..
2. Input the general equation of the infinite series and substitute 5 to x using the CALC function to display the 6th term..And press =
[INDENT][url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20\left%20(%20-\frac{1}{5}%20\right%20)^{x}[/url][/INDENT]

20. Rationalize the given equation:

http://latex.codecogs.com/png.latex?\small \fn_cm \frac{4+3i}{2-i}​

A. 2-5i
B. (5+10i)/6
C. 1+2i
D. (2+i)/3

1. Set the calculator to COMPLEX mode..MODE>2
2. Input the equation as it is in the calculator..(NOTE: The imaginary i is found by pressing the ENG key..
3. Then press =

And you will get the answer..

​

shift>stat ko sa fx-991ES PLUS hangang 6 lang po. pano ung y-hat?

 

[julicar]

Re: Additional Exercises - PART 2

Share ko lng po DL nyo lng pdf po yan credit ko yan ka Engr. Arvie Ogang sana makatulong po!!

https://l.facebook.com/l.php?u=http...math_calculator_-_Solution-1.html&h=fAQF1yU2D View attachment 257928 same lng ng kay R. T.

 

[alaxanfr]

Re: Additional Exercises - PART 2

shift>stat ko sa fx-991ES PLUS hangang 6 lang po. pano ung y-hat?

y-hat is shift-stat(1)-reg(5) -(5)y na may arrow sa taas

 

[joseanpaul]

Re: [tut] math - calculator technique

thanks dito marerecall ko ulit yung mga pinag-aralan ko..

 

[haizt07]

pa-bm TS ..malaking tulong ituu

 

[tratatattt]

Re: Additional Exercises - PART 2

16. What is the sum of the first 20 terms of the sequence: 1, 3, 5, 7...
A. 361
B. 391
C. 400
D. 441

1. Set the calculator to STAT mode: MODE 3>2 (since it is A.P.)
2. In the X column, input 1,2,3..In the Y column, input 1,3,5..
3. After you input the data, press AC..Don't worry your data will not be deleted (unless you change your mode)
4. Press SHIFT>LOG(found below the ON KEY)..we will use the SUMMATION function..(SUMMATION symbol is like E)
5. Press ALPHA>)(for X)>SHIFT>1>7>5(for Y-hat)>SHIFT>)(for comma)>1>SHIFT>)(for comma)>21>)
6. You will noticed that our summation is from 1 to 21..Why 21 and not 20?..Because we start our progression in 1..If we start the progression from 0, then that's the time we use 0 to 20..

And it will be like this..walang Y-hat na symbol e..
[INDENT][url]http://latex.codecogs.com/png.latex?\small%20\fn_cm%20\sum%20(X(Y-Hat),1,21)[/url][/INDENT]

And you will get the answer..

I think it should be 20 not 21

What is the sum of the first 20 terms of the sequence: 1, 3, 5, 7...
1st term is 1
2nd term is 3
3 =5
4 =7
5 =9
6=11
7-13
8=15
9=17
10=19
11=21
12=23
13=25
14=27
15=29
16=31
17=33
18=35
19=37
20=39
summation of 1-20
1+3+5+7+9+11+13+15+17+19+21+23+25+27+29+31+33+35+37+39
is equal to 400
or using the formula
Sn=n(a1+an)/2
that would be
S20=20(1+39)/2 is equal to 400

please tell me if i got it irght or wrong


saka sir sana po matulungan nyo ako
sir ano ano po bang mga libro or any reference ang marerekomenda nyo po saakin
sa pupuntahan ko po kasing review center
di daw masyadong mag fofocus sa calculator techniquesupset:
more on manual calculation daw po sila
para sa REE po sana
salamat

 

[Ruel Cedeno]

ang ganda ng post malaking tulong nito..dagdag ko lng sa half mo

dahil walang nakalagay nakong anung order of reaction pwd tayong mag assume na first order reaction na

at ito ang formula sa first order reaction..

t1/2=(ln 2 )/ k

An=Ao e^-kt

where:

k - rate constant value
An - amount after t
Ao - initial amount
t1/2 - half life

sa problem na ito kkunin muna natin kung value ng k then substitute natin yung nakuhang value ng k sa t1/2 value..

That's right. All nuclear reactions are first order. Since it is stated that it is a radioactive decay, then it is always first order.

 

[Pupina]

I need this salamat TS