Question

What are the first two derivatives of `y = 2sin(3x) - 5sin(6x)`?

Answer 1

You can use the Chain Rule to deal with the arguments of the trig functions:
`y'=2×3cos(3x)-5×6cos(6x)=`
`=6cos(3x)-30cos(6x)`
Then:
`y''=-6×3sin(3x)+6×30sin(6x)=`
`=-18sin(3x)+180sin(6x)`