如何将函数y=sinx+cosx化为y=Asin（x+φ）+k的形式?

网友回答

y=sinx+cosx
＝√2（√2/2sinx+√2/2cosx)
＝√2sin(x+π/4)
======以下答案可供参考======
供参考答案1:
可以当公式记sinx+cosx＝√2sin(x+π/4)
供参考答案2:
y=√2(sinx*√2/2+cosx*√2/2)
=√2(sinxcos(π/4)+cosxsin(π/4))
=√2sin(x+π/4)