Question

If θ is an acute angle of a right angled triangle, then which of the following equation is not true?

Options

• sin θ cot θ = cos θ

• cos θ tan θ = sin θ

• cosec² θ – cot² θ = 1

• tan² θ – sec² θ = 1

Answer 1

tan² θ – sec² θ = 1

Explanation:

tan² θ – sec² θ = 1 is not true

∵ sec² θ = 1 + tan² θ

or sec² θ – tan² θ = 1