Prove each of the following identities:

sin θ (1 + tan θ) + cos θ (1+ cot θ) = (sec θ + cosec θ)

Consider the left – hand side:

L.H.S. = sin θ (1 + tan θ) + cos θ (1+ cot θ)


= sin θ (1 + ) + cos θ (1+ )


= sin θ × (cos θ) ×


= (cos θ + sin θ)


= (cos θ + sin θ)


=


=


= cosec θ + sec θ


= R.H.S.


Hence, proved.


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