Question

how can i input these into my graphing calculator to verify my answer, i have a ti-84

Answer 1

I'm guessing you have graphed the equations already?

Answer 2

If so, then you would hit the "2nd" key, then hit the "trace" button to bring up the "calc" menu. The "calc" stands for "calculate" not calculus, but it does have calculus stuff in here.

Answer 3

then you go to option 7 to get the integral

Answer 4

i graphed it, but nothing comes up in the graph, it stays forever like that then when it's ready nothing comes up

Answer 5

what did you type in?

Answer 6

exactly what you just gave me the 2nd trace cal buttons

Answer 7

well you have to have the graph set up first

Answer 8

do you have y = x^2 - 4 graphed?

Answer 9

make sure the graph shows up when you hit the graph button

Answer 10

yes i have that in y=

Answer 11

and you see the parabola?

Answer 12

no...

Answer 13

ok your window is off then

Answer 14

hold on maybe i input it wrong in my y =

Answer 15

hit the "zoom" key, then hit "6" for standard zoom

Answer 16

okay i had my settings wrong it was too zoomed in, but i did type it correctly!:)

Answer 17

from then what do i need from the graphing calculator

Answer 18

under Category, choose fnInt( . The syntax is fnInt( function, lower limit, upper limit)

Answer 19

xxferrocixx, that's one way to do it, but this way adds the visual shading as well

Answer 20

anyways, you hit

2nd ---> trace ---> 7

to get the integral

Answer 21

sorry the syntax is fnInt( function, x, lower limit, upper limit)

Answer 22

then input your limits of integration and it will shade the appropriate region and give the approximate result. The TI-84 will not provide the exact result if the exact result is like pi/4 or something

Answer 23

if you don't care about the graph portion and you just want the numerical result, then you can follow these button sequences


math key ---> 9

that brings up the fnInt function. The syntax of that function is given by xxferrocixx

So in this case

fnInt(x^2 - 4, x, -1, 1)

is what you type in

Answer 24

x=0, y=-4 those?

Answer 25

where are you getting x = 0 and y = -4 ?

Answer 26

lower limit? thats what pops out when i did the 2nd trace 7

Answer 27

oh ok

Answer 28

type in -1 for the lower limit

Answer 29

1 is the upper limit

Answer 30

hopefully you see the limits on problem #2

Answer 31

1 is the answer? i got something totally different i got a fraction...

Answer 32

(-1/3 -4) 11/3

Answer 33

-1/3 +4

Answer 34

hmm odd

Answer 35

okay my answer was wrong....

Answer 36

you should have gotten this

Answer 37

i will try the next one

Answer 38

try to get what I got

Answer 39

yes!!!

Answer 40

you have x^2 - 4 typed in, so that's good so far

Answer 41

yea, i dont know where i went wrong

Answer 42

you hit 2nd, then trace right?

Answer 43

then you typed -1 for the lower limit
and 1 for the upper limit?

Answer 44

it should work and I don't think it produces fractions

Answer 45

unfortunately the decimal numbers the calculator produces are approximations and not exact answers that this webassign thing may want; however, it is still a useful tool to confirm the answer

Answer 46

i got it!!!!!! yes, i confirmed it is a useful tool:) Thank you for explaining it to me & also thank you @xxferocixx

Answer 47

From Mathematica 9:
\[\int\limits_{-1}^1 \left(t^2-4\right) \, dt=-\frac{22}{3},\int\limits_1^9 \frac{u-6}{\sqrt{u}} \, du=-\frac{20}{3} \]Mathematica also can produce plots