# Homework Help: Intermediate Value Therom

1. Oct 16, 2007

### Dynex

Hey i was jus wondering how to solve this equation i need to find a value of x when subsituted in the eqn is less than 0 so a negative value and a value of x when substituted into the eqn is greater than 0 so a positive value
this will prove that a root exists between those domains (ie. Intermediate value theorm)

p(x)=60x(1+x)^72-(1+x)^72+1

Thankz for the help

2. Oct 16, 2007

### rocomath

if you're trying to test for a # greater/less than 0, just set your equation equal to 0 and solve for x. then choose values greater/less than the value you found.

3. Oct 16, 2007

### Dynex

hey yea thats wa i was plannin on doing but since its like ^72 i cant figure that part out

4. Oct 16, 2007

### EnumaElish

Just by staring at p(x) you can tell one root. Can you guess?

5. Oct 16, 2007

### Dynex

is it 0 -1 or 1

6. Oct 16, 2007

### EnumaElish

Whcih do you think?

7. Oct 16, 2007

### Dynex

hmmm ill go with -1 ?

8. Oct 16, 2007

### EnumaElish

Okay, plug in x = -1. What do you get?

9. Oct 16, 2007

### rocomath

"middle-term"

10. Oct 16, 2007

### Dynex

i got a value of 1

11. Oct 16, 2007

### Dynex

which is greater than 0 so now i need to find a value where f(x)<0

12. Oct 16, 2007

### Dynex

any ideas?

13. Oct 16, 2007

### EnumaElish

I'd try the next integers to either side.

14. Oct 16, 2007

### Dynex

when i tried 2 , 3 and four i got really large numbers

15. Oct 16, 2007

### EnumaElish

You are not paying attention to the polynomial's terms.