Q19 of 48 Page 84

Prove the following with the help of identities:

sin2θ cosθ + tanθsinθ + cos3θ = secθ

Taking L.H.S we get,


Rearranging the terms ;


Sin2 θ.cos θ + cos3 θ + tan θ.sin θ


⇒ cos θ(sin2 θ + cos2 θ) + tan θ.sin θ


⇒ cos θ (1) +


⇒ cos θ +


⇒


⇒ = sec θ


= R.H.S


Hence, proved.


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