已知cos∝=-3⼀5求sin(3π+∝)cos(π⼀2+∝)⼀sin(2π-∝)tan(π+∝)

2025-04-04 15:37:43
推荐回答(1个)
回答1:

sin(3π+α)cos(π/2+α)/sin(2π-α)tan(π+α)
=sin(-α)sinα/sin(-α)tanα
=-sinα*sinα/-sinα*(sinα/cosα)=cosα=-3/5