已知cos(θ+π/6)=（-根号2）/4,且θ为锐角,求sinθ的值?

Question

已知cos(θ+π/6)= （-根号2）/4,且θ为锐角,求sinθ的值?

Answer 1

cos(θ+π/6)= （-根号2）/4且θ为锐角,则sin(θ+π/6)= √14/4
sinθ=sin[(θ+π/6)-π/6]=sin[(θ+π/6)cosπ/6- cos(θ+π/6)sinπ/6=(√42+√2)/8