Question

怎么化简？？

Answer 1

根号下cosQ^2+3cosQ^2-4cosQ+1+3sinQ^2
=根号下cosQ^2-4cosQ+1+3
=根号下cosQ^2-4cosQ+4
=根号下（cosQ-2）^2
=2-cosQ

Answer 2

4cosa^2+3sina^2-4cosa+1
=3(cosa^2+sina^2)+cosa^2-4cosa+1
=cosa^2-4cosa+4
=(cosa-2)^2
所以原式=根号(cosa-2)^2=2-cosa

找不到符号，我用a来表示