Question

Question 22 : part after 'OR'

Answer 1

$a^2\sec^2 \theta-b^2\tan^2 \theta=c^2\\\\\\\dfrac{a^2}{cos^2\theta}-\dfrac{b^2sin^2\theta}{cos^2\theta}=c^2\\\\\\\dfrac{a^2-b^2\sin^2\theta}{\cos^2\theta}=c^2\\\\\\a^2-b^2\sin^2\theta=c^2\cos^2\theta\\\\a^2-b^2\sin^2\theta=c^2(1-sin^2\theta)\\\\a^2-b^2\sin^2\theta=c^2-c^2sin^2\theta\\\\c^2sin^2\theta-b^2\sin^2\theta=c^2-a^2\\\\(c^2-b^2)sin^2\theta=c^2-a^2\\\\\\sin^2\theta=\dfrac{c^2-a^2}{c^2-b^2}$