化简;sina+cosa:和sina -cosa
问题描述:
化简;sina+cosa:和sina -cosa
答
sina+cosa=√2(√2/2×sina+√2/2×cosa)
=√2(cos(π/4)×sina+cos(π/4)×cosa)
=√2(sin(a+π/4))
同样sina -cosa=√2(sin(a-π/4))