sinπ/8×cosπ/8等于多少?

问题描述:

sinπ/8×cosπ/8等于多少?

sinπ/8×cosπ/8+cosπ/8×sinπ/8=sinπ/4=√2/2
2sinπ/8×cosπ/8=√2/2
sinπ/8×cosπ/8=√2/4