求值cos(arcsin3/5+2arctan2)
6.7.(5).2sinπ/4x (6)arctan2
求值:cos(arcsin√3/2)=
已知cos(a/2)-sin(a/2)=1/5,求值tan a
求值4sin^2a-3sinacosa-5cos^2a
已知cos2α=3/5,求值:cos^2α+sin^4α
求值sin(9兀/4)+cos(2兀/3)+tan(5兀/4)
已知(tanα-3)(sinα+cosα+3)=0 求值(1) 4sinα+2cosα/5cosα+3sinα (2)
已知sinα+cosα=1/5,求值:(1)sinαcosα;(2)sin³α+cos³α;(3)s
求值:cos^2 1度+cos^2 2度+…+cos^2 180度=___.
求值:cos 派/7 + cos 3派/7 + cos 5派/7
若cos(π/4+x)=3/5,求值
求值:3−sin70°2−cos