化简 -根号3sin平方x+sinxcosx,
问题描述:
化简 -根号3sin平方x+sinxcosx,
答
sin(2x-60度)+(根号3)/2
答
-根号3sin平方x+sinxcosx
= -根号3【1-cos2x】/2+1/2sin2x
=-根号3/2+根号3/2cos2x+1/2sin2x
=-根号3/2+sinπ/3cos2x+cosπ/3sin2x
=-根号3/2+sin[2X+π/3]