If sec 4A = cosec (A – 20°), where 4A is an acute angle, find the value of A

Solution:

We will be using the trigonometric ratios of complementary angles to solve the given question.

Given that, sec 4A = cosec (A - 20°) ….(i)

sec A = cosec (90° - A)

By using property in equation (i) we get:

cosec (90° - 4A) = cosec (A - 20°)

90° - 4A = A - 20°

5A = 110°

A = 110°/5

A = 22°

☛ Check: NCERT Solutions for Class 10 Maths Chapter 8

Video Solution:

If sec 4A = cosec (A - 20°), where 4A is an acute angle, find the value of A

Maths NCERT Solutions Class 10 Chapter 8 Exercise 8.3 Question 5

Summary:

If sec 4A = cosec (A - 20°), where 4A is an acute angle, then the value of A is 22°.

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