f(x)=3根号15sinx-3根号5cosx化简
问题描述：
f(x)=3根号15sinx-3根号5cosx化简
答
3√15 sin(x) - 3√5 cos(x)
= 3√5 ( √3 sin(x) - cos(x))
= 6√5 ( √3/2 * sin(x) - 1/2 * cos(x))
= 6√5 ( cos(π/6) sin(x) - sin(π/6) cos(x) )
= 6√5 sin(x - π/6)
答
f(x)=3√15sinx-3√5cosx
=6√5(√3/2*sinx-1/2*cosx)
=6√5[sinxcos(π/6)-cosxsin(π/6)]
=6√5sin(x-π/6).