已知(sinα+cosα)/(sinα-cosα)=3,求[sin²(2π-α)+cot(3/2*π-α)]/[tan(π+α)(1+sin²
问题描述:
已知(sinα+cosα)/(sinα-cosα)=3,求[sin²(2π-α)+cot(3/2*π-α)]/[tan(π+α)(1+sin²
高手帮帮忙啊~~~
已知(sinα+cosα)/(sinα-cosα)=3,求[sin²(2π-α)+cot(3/2*π-α)]/[tan(π+α)(1+sin²α)]
不好意思啊,我以为全发了的说……
答
将(sinα+cosα)/(sinα-cosα)=3变形整理,可得sinα=2cosα,或tanα=2[sin²(2π-α)+cot(3/2*π-α)]/[tan(π+α)(1+sin²α)]=[sin²α+tanα]/[tanαcos²α]=[sin²α+2]/[2cos²...