The equation tan theta sin thetacos theta is an identity Ho
     The equation tan theta = sin theta/cos theta is an identity. However, there are certain points where this equality is not true. State all the theta-values in which tan theta = sin theta/cos theta is false. 
  
  Solution
It is not true when cos theta=0
ANd cos theta is 0 at (2n+1)pi/2
Therefore tan theta=sin theta/cos theta is not true at (2n+1)pi/2

