Click to Chat

1800-2000-838

+91-120-4616500

CART 0

• 0

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
```        prove that:
cos2Acos2B + sin2(A - B) - sin2(A + B) = cos2(A + B)```
7 years ago

510 Points
```										sin2(A-B) - sin2(A+B) =sin(A+A)sin(-B-B)                                         [using formula ,sin2a-sin2b=sin(a-b)sin(a+b)]
=sin(-2B)sin2A=-sin2Asin2B
now LHS becomes
=cos2Acos2B-sin2Asin2B                        [ using formula ,cosacosb - sinasinb =cos(a+b)]
=cos(2A+2B)=cos2(A+B) = RHS
hence proved
```
7 years ago
44 Points
```										Cos2ACos2B+Sin^2(A-B)-Sin^2(A+B)=Cos2(A+B)
Solution:-
L.H.S:-Cos2ACos2B+Sin^2(A-B)-Sin^2(A+B)
=Cos2ACos2B+Sin(A-B+A+B)*Sin(A-B-A-B)	["a^2-b^2=(a+b)(a-b)"]
=Cos2ACos2B+Sin2A*Sin(-2B)
=Cos2ACos2B-Sin2ASin2B
=Cos2(A+B)			["Cos(A+B)=CosACosB-SinASinB"]

Thank You!!!!!!!!!!!!!!!!!!!!!!
Wish You A Happy Learning Trignometry........
```
7 years ago
Think You Can Provide A Better Answer ?

## Other Related Questions on Trigonometry

View all Questions »
• Complete JEE Main/Advanced Course and Test Series
• OFFERED PRICE: Rs. 15,900
• View Details
Get extra Rs. 2,900 off
USE CODE: CHENNA
Get extra Rs. 636 off
USE CODE: CHENNA