Question

derivative problem help please.

Answer 1

yeah what's up?

Answer 2

whats the question

Answer 3

\[d ^{2}x/dt ^{2} \] if dx/dt= 9x sin x

Answer 4

use the product rule

Answer 5

i get that i just don't understand the second derivative of x.

Answer 6

f"(x) = d/dx f'(x)

Answer 7

same procedure

Answer 8

use your first derivative to find the second

Answer 9

the answer would be 9x((cos(x))+9(sin(x)) because of the product rule :)

Answer 10

yes i understand that. what i mean is that when you take the second derivative of x, it should not equal 1 like it would in the first derivative. i don't know how to find that.

Answer 11

f'(x) = 9(sinx+xcosx)

use that and find it's derivative to find f"(x)
for reference:
f"(x) = 18cos(x)-9xsin(x)

Answer 12

the way you wrote the problem you will have to take the derivative implicitly, treating x as a function of t

Answer 13

use your first derivative to find the second

Answer 14

watch your signs its - not +

Answer 15

so how do i take the derivative implicitly?

Answer 16

have you done implicit differentiation?