Question

If sin 2 theta= cos 3 theta , then find the value of theta

Answer 1

Answer:

18

when sin theta= cos theta then sum of the two theta is 90 so here 2theta +3 theta=90

5 theta=90

theta=18

Answer 2

Given:

Consider the given equation $sin2\theta =cos3\theta$

Find:

The value of $\theta$

Solution:

Consider the given equation $sin2\theta =cos3\theta$

We know that $cos(90-2\theta)= sin\theta$

Therefore

$cos(90-2\theta) =cos3\theta\\\\90-2\theta = 3\theta\\\\5\theta = 90\\\\\theta = \frac{90}{5} \\\\\theta = 18$

The answer is 18.