MY CART (5)

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

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Keshava Naidu Grade: 12th pass
        
prove that cos(6x)=32cos^6(x)-48cos^4(x)+18cos^2(x) -1
2 years ago

Answers : (3)

noogler
489 Points
										
cos6x=cos[2(3x)]=2cos2(3x)-1                                                   cos2x=2cos2x-1
                         =2[cos(3x)]2-1                                                 cos3x=4cos3x-3cosx
                         =2[4cos3x-3cosx]2-1                                       (a-b)2=a2+b2-2ab
                         =2[16cos6x+9cos2x-24cos4x]-1
                         =32cos6x-48cos4x+18cos2x-1
2 years ago
Aman
13 Points
										cos6x=cos[2(3x)]=2cos2(3x)-1                                                   cos2x=2cos2x-1                         =2[cos(3x)]2-1                                                 cos3x=4cos3x-3cosx                         =2[4cos3x-3cosx]2-1                                       (a-b)2=a2+b2-2ab                         =2[16cos6x+9cos2x-24cos4x]-1                         =32cos6x-48cos4x+18cos2x-1
										
6 months ago
kirti
11 Points
										
R.H.S. ==>  cos(6x) = cos 2(3x) = 2cos2(3x) – 1
L.H.S. ==> 32cos6x – 48cos4x + 18cos2x – 1
             => 2(16cos6x – 24cos4x + 9cos2x) – 1
             => 2(4cos3x – 3cosx)2 – 1
             => 2cos2(3x) – 1
L.H.S. = R.H.S.
 
Hence, Proved
4 months ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies
  • Complete JEE Main/Advanced Course and Test Series
  • OFFERED PRICE: Rs. 15,900
  • View Details

Ask Experts

Have any Question? Ask Experts

Post Question

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