sinα是5x²-7x-6=0的根
问题描述:
sinα是5x²-7x-6=0的根
[sin(α+3π/2)·sin(3π/2-α)·tan²(2π-α)·tan(π-α)]÷[cos(π/2-α)·cos(π/2+α)的值
答
[sin(α+3π/2)·sin(3π/2-α)·tan²(2π-α)·tan(π-α)]÷[cos(π/2-α)·cos(π/2+α)
=[-cosa*-cosa*tan²a*-tana]÷【sina*-sina】
=【sin²a*-tana】]÷【-sin²a】
=tana