What is sinx+π2?
Find the value of sin(x+π2):
As we know,
sin(A+B)=sinAcosB+sinBcosA
In the given question, A=x and B=π2
So,
sinx+π2=sinx·cosπ2+sinπ2·cosx=sinx·0+1·cosx∵cosπ2=0andsinπ2=1=cosx
Hence, sin(x+π2)=cosx