Question

If sin 3A = cos (A – 26°), where 3A is an acute angle, find the value of A.

NCERT Class X
Mathematics - Mathematics

Chapter _INTRODUCTION TO
TRIGONOMETRY

Answer 1

sin 3A = cos (A-26 )

cos (90 - 3A) = cos (A-26) [ sinA = cos (90- A )
By comparison

90-3A = A-26

90+26=A+3A
116=4A

A= 29






Be brainliest!

Answer 2

Answer:

A = 29

Step-by-step explanation:

Given : Sin 3A = cos (A – 26°)

To Find : Find Value of A

Solution:

$Sin 3A = Cos ( A-26^{\circ})$

$Sin \theta = Cos (90-\theta)$

$Cos(90-3A) = Cos ( A-26^{\circ})$

So, on comparing angles :

$90-3A=A-26$

$90+26=A+3A$

$116=4A$

$29=A$

So, The value of A is 29 .