Question

If θ is a positive acute angle and cos² θ + cos⁴θ = 1, then the value of tan²θ + tan⁴θ is?

A 1 Correct Answer Incorrect Answer
C √2 Correct Answer Incorrect Answer
D √3 Correct Answer Incorrect Answer

Solution

cos²θ + cos ⁴ θ = 1 cos ⁴ θ = 1 - cos² θ cos ⁴ θ = sin² θ cos² θ= sin² θ/ cos² θ tan²θ = cos² θ tan²θ = cos ⁴ θ tan² θ+ tan ⁴θ = cos² θ + cos ⁴ θ = 1

Practice Next

Relevant for Exams:

×
×