Question #40bb3

1 Answer
Apr 10, 2017

see below

Explanation:

Use the following Composite Argument Properties
color(red)(cos(A-B)=cos A cos B+sinA sinBcos(AB)=cosAcosB+sinAsinB
color(red)(sin(A+B)=sinAcosB+cos A sin Bsin(A+B)=sinAcosB+cosAsinB

Left Hand Side:

color(green)(cos(pi-theta)+sin(pi/2+ theta)=color(blue)(cos picos theta+sin pi sin theta+sin (pi/2) cos theta+cos (pi/2)sin theta cos(πθ)+sin(π2+θ)=cosπcosθ+sinπsinθ+sin(π2)cosθ+cos(π2)sinθ

color(blue)(=-1*cos theta+0*sin theta+1*cos theta+0*sin theta=1cosθ+0sinθ+1cosθ+0sinθ

color(blue)(=-cos theta+cos theta)=cosθ+cosθ

color(blue)(=0)=0

color(blue)( :.= Right Hand Side