求值sin(9兀/4)+cos(2兀/3)+tan(5兀/4)
问题描述:
求值sin(9兀/4)+cos(2兀/3)+tan(5兀/4)
答
sin(9兀/4)+cos(2兀/3)+tan(5兀/4)
=sin(2π+π/4)+cos(π-π/3)+tan(π+π/4)
=sinπ/4-cosπ/3+tanπ/4
=√2/2-1/2+1
=√2/2+1/2