Question #7facb

1 Answer
Mar 1, 2017

see below

Explanation:

I think you meant to write pi/4π4 instead of pi4π4. So here it is with pi/4π4

Right Hand Side:
Use the formula cos(A+B)=cosAcosB-sinAsinBcos(A+B)=cosAcosBsinAsinB

sqrt2 cos(pi/4+theta)=sqrt2[cos (pi/4) cos theta-sin(pi/4) sin theta] 2cos(π4+θ)=2[cos(π4)cosθsin(π4)sinθ]

=sqrt2[1/sqrt2 cos theta-1/sqrt2 sin theta]=2[12cosθ12sinθ]

=sqrt2/sqrt2 cos theta-sqrt2/sqrt2 sin theta=22cosθ22sinθ

=cancel(sqrt2/sqrt2) cos theta-cancel(sqrt2/sqrt2) sin theta

=cos theta-sin theta

:.= Left Hand Side