急...求导y=2x乘以cos(2x+π/6)

问题描述:

急...求导y=2x乘以cos(2x+π/6)

y=2xcos(2x+π/6)
y'=2cos(2x+π/6)-2xsin(2x+π/6)*2
=2cos(2x+π/6)-4xsin(2x+π/6)

y'=(2x)' cos(2x+π/6)+2x[cos(2x+π/6)]'
=2cos(2x+π/6) - 4xsin(2x+π/6)