If sin θ +cos θ =p and sec θ +cosec θ =q, then prove that q(p2 - 1)=2p.


Given that sin θ + cos θ = p and sec θ + cosec θ = q

Taking sec θ + cosec θ = q






Squaring sin θ + cos θ = p,


We have (sin θ + cos θ)2 = p2


sin2 θ + cos2 θ + 2 sin θ cos θ = p2


1+2 sin θ cos θ = p2 [,sin2 θ + cos2 θ = 1]




q+2p = p2 q


q (p2 – 1) = 2p


Hence, proved.


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