Question

Differentiate y=sin3x then dy/dx =?

Answer 1

The answer `dy/dx=3*cos3x`

Explanation:

`y=sin3x`

`dy/dx=3*cos3x`

Answer 2

`3cos(3x)`

Explanation:

Given: `y=sin(3x)`.

Use the chain rule, which states that,

`dy/dx=dy/(du)*(du)/dx`

Let `u=3x,:.(du)/dx=3`.

Then, `y=sin(u),:.dy/(du)=cos(u)`.

Combining our results, we get,

`dy/dx=cos(u)*3`

`=3cos(u)`

Substitute back `u=3x`, we get:

`=3cos(3x)`