sin2x+cos2x=根号2sin(2x+四分之派)怎么求的
问题描述:
sin2x+cos2x=根号2sin(2x+四分之派)怎么求的
答
sin2x+cos2x
=√2(√2/2·sin2x+√2/2·cos2x)
=√2(sin2xcosπ/4+cos2xsinπ/4)
=√2sin(2x+π/4)