Simplify the trigonometric expression cos x sin2 X cos3 X S
     Simplify the trigonometric expression. cos x sin^2 X + cos^3 X   
  
  Solution
cosxsin2x +cos3x
=>cosxsin2x +cosxcos2x
take cosx as common term
=>cosx(sin2x +cos2x)
=>cosx *1..........................................................[since sin2x +cos2x=1 is an identity]
=>cosx
therefore cosxsin2x +cos3x=cosx

