RRB Junior Engineer / DMS / CMA 2019 · Question 2441 of 3719

If $$x = a \sec \theta + b \tan \theta and y = a \tan \theta + b \sec \theta$$, then find $$x^2 - y^2$$.

1. A$$a^2 - b^2$$Correct
2. B$$a + b$$
3. C$$a^2 + b^2$$
4. D$$\sqrt{a^2 + b^2}$$