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.
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
Grade: 10

                        

In triangle ABC a²sin2B - b²sin2A then find the value of it

2 years ago

Answers : (1)

Arun
25089 Points
							
a²sin2B + b²sin2A = c²cotC/2 
4R².sin²A.sin2B + 4R².sin²B.sin2A = 4R².sin²C.cotC/2 
sin²A.sin2B + sin²B.sin2A = sin²C.cotC/2 
(1 - cos2A)/2.sin2B + (1 - cos2B)/2.sin2A = sin²C.cotC/2 
sin2B - cos2A.sin2B + sin2A - cos2B.sin2A = 2sin²C.cotC/2 
sin2A + sin2B - sin(2A + 2B) = 2sin²C.cotC/2 ( vì sin2A.cos2B + cos2A.sin2B = sin (2A +2B) 
sin2A + sin2B + sin2C = 2sin²C.cotC/2 
2sin(A + B)cos(A - B) + 2sinC.cosC = 2sin²C.cotC/2 
2sinC.[ cos(A - B) - cos(A + B) ] = 2sin²C.cotC/2 
2sinC.-2.sinA.sin(-B) = 2sin²C.cotC/2 
4sinA.sinB.sinC = 2sin²C.cotC/2 
2sinA.sinB = sinC.cotC/2 
2sinA.sinB = 2sinC/2.cosC/2.cosC/2 /sinC/2 
sinA.sinB = cos²C/2 
2sinA.sinB = 1 + cosC 
2sinA.sinB = 1 - cos(A + B) 
2sinA.sinB = 1 - cosA.cosB + sinA.sinB 
cosA.cosB + sinA.sinB = 1 
cos(A - B) = 1 
A = B A - B =0
2 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


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