Question

Differentiate:
y= -8tan(cosx)

Answer 1

use the chain rule :
derivative of cos(...) is -sin(...)
derivative of tan(..) is sec^2 (..)

Answer 2

but the tan encompasses the entire (cos x)....

Answer 3

Repeated chain rule.

Answer 4

let cosx = u
derivative of tan(u) = sec^2 u
subtitute back u =cosx

Answer 5

ummm. ok lemme try that out. I'll post the answers iiget when i'm done.

Answer 6

@ParthKohli so dy/dx= [(-sinx)(-8sec^2(cosx))]

Answer 7

Yes! Now simplify it and you are done.