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
Zeppelin Grade: 11
        
find the expression cot9+cot27+cot63+cot81
2 years ago

Answers : (1)

Shubham Kamleshbhai Patel
59 Points
										
In this case u need grouping.
 
=> (cot 9° + cot 81°) + (cot 27° + cot 63°)
Convert cot to sin and cos
 
=> [(cos 9° / sin 9°) + (cos 81° / sin 81°)] + [(cos 27° / sin 27°) + (cos 63° / sin 63°)]
 Using cross-multiplication,
=>[(sin 81° . cos 9° + cos 81° . sin 9°)/(sin 9° . sin 81°)] + [(sin 63°. cos 27° + cos 63° . sin 27°)/(sin 27° . sin 63°)]
 
Solving it, u will get the answer as 4√5.
2 years 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
Get extra Rs. 2,385 off
USE CODE: COUPON10
Get extra Rs. 95 off
USE CODE: COUPON10

Ask Experts

Have any Question? Ask Experts

Post Question

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