Question

(Bihar 2009A]
16. (sec A-cos A)(cot A+tan A) = tan A sec A.​

Answer 1

Taking L.H.S..

LHS=

(secA-cosA) (cotA+tanA)

= (1/cosA - cosA) * cosA/sinA + sinA/cosA)

=(1-cos²A)/cosA * (sin²A + cos²A ) / sinA cosA)

={(sin²A) /cosA}*(1/sinA cosA)

=sinA/cos²A = (sin A/cosA)*(1/cosA)

=tanA*secA=RHS

Hence Proved!!

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