NCERT Class 11-Math՚S: Chapter 3 Exemplar Trigonometric Functions Part 13 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Long Answer Type

Question 20:

If then prove that

Answer:

Given,

prove:

As, LHS

Using:

It involves terms so we need to calculate it first.

Similarly,

Using:

Thus,

Question 21:

If , then prove that

Answer:

Given,

To prove: .

Applying componendo – dividend, we get

From transformation formula, we know that –

Question 22:

Find the value of the expression

Answer:

Let,

We know that-