Question

How do you differentiate # f(x) =cos(3x -2) #?

Answer 1

`(df)/dx = -3sin(3x-2)`

Explanation:

Use substitution.

If you have a function like this, let,say, `t =3x -2`
Then `f(t) = cost` and `(df)/dt = -sint`
`(dt)/dx = 3`
`(df)/dx = (df)/dt*(dt)/dx = -sint*3`

`(df)/dx = -3sin(3x-2)`