Thank you for registering.

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

Please check your email for login details.
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

if cosx + cosy=4/5 and cosx - cosy=2/7 prove that 14tan(x-y/2)+5cot(x+y/2)=0

if cosx + cosy=4/5 and cosx - cosy=2/7 prove that 14tan(x-y/2)+5cot(x+y/2)=0

Grade:11

3 Answers

Lab Bhattacharjee
121 Points
5 years ago
\text{Prosthaphaeresis Formulas}\\ \cos x+\cos y=2\cos\dfrac{x+y}2\cos\dfrac{x-y}2\\ \text{ and } \cos x-\cos y=-2\sin\dfrac{x+y}2\sin\dfrac{x-y}2\text{Using Prosthaphaeresis Formulas}\\ \cos x+\cos y=2\cos\dfrac{x+y}2\cos\dfrac{x-y}2\\ \text{ and } \cos x-\cos y=-2\sin\dfrac{x+y}2\sin\dfrac{x-y}2
girish
14 Points
5 years ago
adding both you get cosx subtracting cosy so we also got sinx and siny if we use half angle formulas we can write sinx in terms of tanx/2 so we got that too so we can solve
Gowri sankar
292 Points
5 years ago
This question solve using half angle formulas we can write sinx in terms of tanx/2 so we got that then solve this problem.

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

ASK QUESTION

Get your questions answered by the expert for free