-2cos(x²-x){-sin(x²-x)}(2x-1)怎么化简,
问题描述：
-2cos(x²-x){-sin(x²-x)}(2x-1)怎么化简,
答
-2cos(x²-x)[-sin(x²-x)](2x-1)
=[2cos(x²-x)sin(x²-x)](2x-1)
=(2x-1)sin(2x²-2x)=[2cos(x²-x)sin(x²-x)](2x-1)这一步到下一步的公式是什么呀1拜托了2倍角公式：sin(2a)=2sinacosa