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#