Question

let f(x)=g(x)h(x), g(10)=-4, h(10)=560, g'(10)=0, and h'(10)=35. Find f'(10)

Answer 1

Do I have to use the slope of the tangent line?

Answer 2

Have you considered the Product Rule?

f'(x) = g(x)h'(x) + g'(x)h(x)

Should be familiar.

Answer 3

Ohhh yeah

Answer 4

Let me try it :)

Answer 5

(-4)(35)+(560)(0)

=140

Answer 6

f'(x) = g(x)h'(x) + g'(x)h(x)
g(10)=-4, h(10)=560, g'(10)=0, and h'(10)=35
f'(10) = (-4)(35) + (0)h(x) = -140

You were SO CLOSE!!

Answer 7

oops forgot about the (-) sign hehe thanks ^_^

Answer 8

Notice how I didn't bother to substitute for h(10). No matter what it is, the product woudl be zero, so I stopped.