已知cos(x+45°)=0.6 求(1)sin2x (2)若17π/12<x<7π/4 则(sinx +sin2x·tanx)/(1-tanx)已知cos(x+45°)=0.6 求(1)sin2x (2)若17π/12<x<7π/4 则(sinx +sin2x·tanx)/(1-tanx)
问题描述:
已知cos(x+45°)=0.6 求(1)sin2x (2)若17π/12<x<7π/4 则(sinx +sin2x·tanx)/(1-tanx)
已知cos(x+45°)=0.6 求(1)sin2x (2)若17π/12<x<7π/4 则(sinx +sin2x·tanx)/(1-tanx)
答