Question

How do you differentiate `2cos(x)+cos^2(x)`?

Answer 1

`-2sinx-sin2x`

Explanation:

`d/dx(2cosx+cos^2x)`
`" "`
`=d/dx(2cosx)+d/dx(cos^2x)`
`" "`
`=2(d/dx(cosx))+2cos^(2-1)x(d/dx(cosx))`
`" "`
`=2(-sinx)+2cosx(-sinx)`
`" "`
`=-2sinx-2cosxsinx`
`" "`
`=-2sinx-sin2x`