设α为锐角,若cos(α+π/6)=4/5,求sin(2α+π/12),
cos(α+π/6)=4/5
sin(α+π/6)=3/5,
sin(2α+π/3)=24/25
cos(2α+π/3)=7/25
sin(2α+π/12)=sin(2α+π/3-π/4)=31√2/50
设α为锐角,若cos(α+π/6)=4/5,求sin(2α+π/12),
cos(α+π/6)=4/5
sin(α+π/6)=3/5,
sin(2α+π/3)=24/25
cos(2α+π/3)=7/25
sin(2α+π/12)=sin(2α+π/3-π/4)=31√2/50