求sinπ/8cosπ/8的值

问题描述:

求sinπ/8cosπ/8的值

原式 = 1/2 * 2sinπ/8cosπ/8
=1/2 * sin(π/8*2)
=1/2sinπ/4
=根号2/4

1/2sinpi/4=1/2*根号2/2=根号2/4