Using the Intermediate Value Theorem, show that the function f has a zero between a and b. f(x)=x^3+4x^2-8x-10 a=-6, b=-5 What is f(-6)? What is f(-5)? Is there a zero between x= -6 and x= -5?

Question

Using the Intermediate Value Theorem, show that the function f has a zero between a and b. f(x)=x^3+4x^2-8x-10     a=-6, b=-5     What is f(-6)?    What is f(-5)?    Is there a zero between x= -6 and x= -5?

anonymous · Answer

f(-6) means you substitute in -6 everywhere you see an x in the function.
f(-5) means you substitute in -5 everywhere you see an x in the function.

Once you compute those values, if one is positive and one is negative, what must happen to the function between those two numbers?

anonymous · Answer

i have no idea :S

anonymous · Answer

Okay, I'll show you -6.

f(-6) = (-6)^3 + 4(-6)^2-8(-6)-10
        = -216 + 144 + 48 - 10 
        = -34

anonymous · Answer

how are you getting 4(-6)^2 = 144? sorry im really bad at this

anonymous · Answer

(-6)^2 = (-6) * (-6) = 36

Multiply 36 by 4 = 144