Find y" if y=2x cosx

y2x-cosx

#1

find y" if y=2x cosx

Answer:

y’=(2)(cosx)+(2x)(-sinx) Product rule- f’xgx+fxg’x
y’=2cosx+2xsinx
y’’=2*-sinx+((2)(sinx)+(2x)(cosx)) product rule
y’’=-2sinx+(2sinx+2x(cosx))