Question

Sec^2 θ – Sec^4 θ equals to _____

(a) –Sec^2 θ Tan^2 θ

(b) – Sec^2 θ Tan^2 θ

(c) 1

(d) 0

This question was posed to me during an online exam.

I'm obligated to ask this question of Trigonometric Identities topic in division Trigonometry of Mathematics – Class 10

Answer 1

Right answer is (a) –Sec^2 θ Tan^2 θ

The explanation: Sec^2 θ – Sec^4 θ = Sec^2 θ (1 – Sec^2 θ) (∵ sec^2 θ – tan^2 θ = 1)

= Sec^2 θ (-Tan^2 θ)

= -Sec^2 θ Tan^2 θ