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: 11
        
SecA – CosA =1,then tan2A/2=?
5 years ago

Answers : (1)

Jitender Singh
IIT Delhi
askIITians Faculty
158 Points
							
Ans:
secA-cosA = 1
\frac{1}{cosA}-cosA = 1
1-cos^{2}A = cosA
cos^{2}A+ cosA-1=0
cosA = \frac{-1\pm \sqrt{5}}{2}
cosA = \frac{-1+\sqrt{5}}{2}
cosA=1-2sin^{2}\frac{A}{2} = \frac{-1+\sqrt{5}}{2}
2-4sin^{2}\frac{A}{2} = \frac{-1+\sqrt{5}}{1}
4sin^{2}\frac{A}{2}=3-\sqrt{5}
sin^{2}\frac{A}{2}=\frac{3-\sqrt{5}}{4}
cos^{2}\frac{A}{2}=1-sin^{2}\frac{A}{2}=1-\frac{3-\sqrt{5}}{4}=\frac{1+\sqrt{5}}{4}
tan^{2}\frac{A}{2}=\frac{sin^{2}\frac{A}{2}}{cos^{2}\frac{A}{2}}=\frac{3-\sqrt{5}}{1+\sqrt{5}}
Thanks & Regards
Jitender Singh
IIT Delhi
askIITians Faculty
5 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