badge image

Enroll For Free Now & Improve Your Performance.

×
User Icon
User Icon
User Icon
User Icon
User Icon

Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
Close

MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

⇐ BackProceed to Checkout ⇒
There are no items in this cart.
Continue Shopping
Menu
Grade: 12th pass 

                        
Prove that , (sinX) 3 × sin3X + (cosX) 3 × cos3X =(cos2X) 3
2 years ago

Answers : (1)

Susmita
425 Points 
							
Use the formula
sin3x=(3sinx-sin3x)/4
and cos3x=(3cosx+cos3x)/4
also cos3(2x)=(3cos2x+cos6x)/4
Put the first two formula in the given expression.you will get
(3sinxsin3x-sin23x+3cosxcos3x+cos23x)/4
Put 3sinxsin3x+3cosxcos3x=cos(3x-x)=cos2x
And cos23x-sin23x=cos(2.3x)=cos6x.
and see you will get the ans.
 
2 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies

Other Related Questions on Trigonometry

I need to simplify the following question but i didnt get Answer & Earn Cool Goodies
Please give me solutions. Trigonometric equations. JEE Mains Answer & Earn Cool Goodies
Formulas of compound angels And sub multiple angels
1+tan2A/1+cot2A = (A) sec2 A (B) -1 (C) cot2A (D) tan2A
cos 20 cos40 cos 60 cos 80=1/16 please solve it as soon as possible.....
View all Questions »


Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 31 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers To Win!!! Click Here for details