sin^a+cos^(π/6+a)+1/2sin(2a+π/6)求值

问题描述:

sin^a+cos^(π/6+a)+1/2sin(2a+π/6)求值

是不是sin^2a+cos^2(π/6+a)+1/2sin(2a+π/6)
=(1-cos2a)/2+(1+cos(π/3+2a))/2+1/2sin(2a+π/6)
=1-1/2cos2a+1/4cos2a-√3/4sin2a+√2/4sin2a+1/4cos2a (利用公式展开)
=1不是诶,可能书上有错,这样能算出来吗sin^a是什么意思?是(sinx)^a吗?是sina的平方我写的就是这个意思(sina)^2+[cos(π/6+a)]^2+1/2sin(2a+π/6)=(1-cos2a)/2+(1+cos(π/3+2a))/2+1/2sin(2a+π/6)=1-1/2cos2a+1/4cos2a-√3/4sin2a+√2/4sin2a+1/4cos2a (利用公式展开)=1