Welcome Visitor! Login | Sign Up | Help!

Refer a Friend

|

Follow us on:

Advanced

More

Home » Ask & Discuss » Mathematics
« Back to Discussion



Trignometry
chaitanya
New kid on the Block

Joined: 4 Mar 2012
Post: 1
4 Mar 2012 13:48:28 IST
1 People liked this
1
624 View Post
cot(A+15)-tan(A-15)=4cos(2x)/(1+2sin(2A))
Engineering Entrance , JEE Main , JEE Main & Advanced , Mathematics , Trigonometry

cot(A+15)-tan(A-15)=4cos(2x)/(1+2sin(2A))


Comments (1)

Sumiran agrawal's Avatar

Sumiran agrawal
Scorching goIITian

Joined: 20 Jul 2011
Posts: 256
4 Mar 2012 14:59:57 IST
1 people liked this

 First of all, the question is cot(A+15)-tan(A-15) = 4cos2A / 1+2sin2A ( You have posted x instead of A)

Now taking L.H.S

cot(A+15) - tan(A-15)

cos(A+15) / sin(A+15)   -   sin(A-15) / cos(A - 15)

[cos(A+15)cos(A-15) - sin(A-15)sin(A+15)] / [ sin(A+15)cos(A-15)

cos2A / sin(A+15)cos(A-15)

2cos2A / 2sin(A+15)cos(A-15)

2cos2A / [sin2A +sin30]

2cos2A / [ sin2A + 1/2]

2cos2A / [(2sin2A+1)/2]

4cos2A / (2sin2A + 1)

= R.H.S

Hence proved....
Reply


Quick Reply


Reply
Some HTML allowed.
Keep your comments above the belt or risk having them deleted.
Signup for a avatar to have your pictures show up by your comment
If Members see a thread that violates the Posting Rules, bring it to the attention of the Moderator Team
Free Sign Up!
Sponsored Ads

Preparing for JEE?

Kickstart your preparation with new improved study material - Books & Online Test Series for JEE 2014/ 2015


@ INR 5,443/-

For Quick Info

Name

Mobile

E-mail

City

Class

Vertical Limit

Top Contributors
All Time This Month Last Week
1. Bipin Dubey
Altitude - 16545 m
Post - 7958
2. Himanshu
Altitude - 10925 m
Post - 3836
3. Hari Shankar
Altitude - 10050 m
Post - 2205
4. edison
Altitude - 10815 m
Post - 7802
5. Sagar Saxena
Altitude - 8625 m
Post - 8064
6. Yagyadutt Mishr..
Altitude - 6330 m
Post - 1979

Find Posts by Topics

Physics

Topics

Mathematics

Chemistry

Biology

Parents Corner

Board

Fun Zone

35,229,755
Engineering Questions Attempted		 6,69,530
Visitors Monthly		 79
Engg. Exam Covered		 1085
Students Currently Online		 Connect with Us

How can we improve this site for you?


Vriti Communities
Privacy Policy © Vriti 2011