How do you simplify cos(x - pi/2)?
Risposta:
sinx
Spiegazione:
We know that ,cos is an even function.=>cos(-theta)=costheta
:.cos(x-pi/2)=cos(pi/2-x)=sinx
OR
cos(A-B)=cosAcosB+sinAsinB
cos(x-pi/2)=cosxcos(pi/2)+sinxsin(pi/2)
cos(x-pi/2)=cosx(0)+sinx(1)=0+sinx=sinx