0

Guest

Courses New

Sin5xcos3x..plxz help me to get out of this question...answer fast....

Sin5xcos3x..plxz help me to get out of this question...answer fast....

Question Image
Grade:11

2 Answers

Saurabh Koranglekar
askIITians Faculty 10335 Points
4 years ago
Dear student

Sin ( a+b)+ sin ( a-b)

= 2 sin a cos b

On simplification of the question

Sin 2x = sin 4 x

2sin x cos x = 2 sin x. Cos x. Cos 2x

Cos 2x = 1

Now you can solve further

Regards
Arun
25750 Points
4 years ago
Dear student 
 
multiply by 2 in LHS and RHS
 
then it becomes after using the formula of 2 sinAcosB
 
sin 8x + sin 2x = sin 8x + sin 4x
 
hence sin 2x = sin 4x
 
sin2x (1 – 2 cos2x) = 0
 
hence sin2x = 0 or cos2x = ½
 
2x = n* pi      or    2x = 2 n* pi ± pi/3
 
x = n * pi/2     or    x = n * pi ± pi/6

Think You Can Provide A Better Answer ?

Other Related Questions on Trigonometry

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More