First slide

Compound angles

Question

If $\sin (x - y) = \cos (x + y) = \frac{1}{2}$ the values of x and y flying between 0° and 90° are given by

Moderate

A

$x = 15^{\circ}, y = 25^{\circ}$
B

$x = 65^{\circ}, y = 15^{\circ}$
C

$x = 45^{\circ}, y = 45^{\circ}$
D

$x = 45^{\circ}, y = 15^{\circ}$

Solution

We have,
$\sin (x - y) = \frac{1}{2} and \cos (x + y) = \frac{1}{2}$
$\begin{array}{l} \Rightarrow (x - y = 30^{\circ}) and (x + y = 60^{\circ}) \\ \Rightarrow x = 45^{\circ}, y = 15^{\circ} \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App