Question

已知:f(a)=sin(-派-a)分之sin(派-a)cos(2派-a)tan(-a+2分之3派) tan(-a-派)

Answer 1

f(a)=sin(π-a)cos(2π-a)tan(-a+3π/2) tan(-a-π) / sin(-π-a)

=sina*cosa*cota*(- tana) /sina

=-cosa

cos(a-3π/2)=1/5=-sina,cosa=-2√6/25,f (a)=2√6/25

f(-1860度）=-cos1860度=-cos(5X360度+60度）=-1/2