sin2xcos2x+sin2x+2cox2x+1怎么化简为一角一函数啊?
问题描述:
sin2xcos2x+sin2x+2cox2x+1怎么化简为一角一函数啊?
尽快在一天之内搞定,
是sin2xcos2x+sin2x+2cos2x+1.
答
sin2xcos2x+sin2x+2cos2x+1=(sin4x)/2+根号5×(sin2x/根号5+2*cos2x/根号5)+1设角a使得cosa=1/根号5,sina=2/根号5则(sin4x)/2+根号5×(sin2x/根号5+2*cos2x/根号5)+1=(sin4x)/2+根号5×(sin2xcosa+cos2xsina)+1=(...