First slide

Trigonometric equations

Question

Number of solutions of $\sin \{x\} = \cos \{x\}$ in $[0, 2 π]$ is (Here $\{x\}$ is fractional part of x)

Moderate

A

4
B

6
C

5
D

7

Solution

$W e h a v e \sin \{x\} = \cos \{x\}$
$\begin{array}{l} \Rightarrow \tan \{x\} = 1 \\ \Rightarrow \{x\} = \frac{π}{4} (o r) \frac{5 π}{4} \end{array}$
$\Rightarrow \{x\} = \frac{π}{4}$
$\Rightarrow x = 0.78, 1.78, 2.78, 3.78, 4.78, 5.78$

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