Hey there! We receieved your request
Stay Tuned as we are going to contact you within 1 Hour
One of our academic counsellors will contact you within 1 working day.
Click to Chat
1800-5470-145
+91 7353221155
Use Coupon: CART20 and get 20% off on all online Study Material
Complete Your Registration (Step 2 of 2 )
Sit and relax as our customer representative will contact you within 1 business day
OTP to be sent to Change
The value of cos 180/11+ cos 3*180/11+cos 5*180/11+cos 7*180/11+cos 9*180/11 is
Dear abhipsa,
we know that
cos a + cos 3a + cos 5a + .. + cos(2n-1)a = sin 2na/2 sin a
In our case n = 5
therefore RHS = sin 10a / (2sina)
=>RHS = sin 2*5 *(180/11) / 2sin (180/11)
=> RHS = sin (180/11) /2 sin(180/11)
=> rhs = 1/2
hence the answer is option 3 ......1/2
GOODLUCK Please feel free to post as many doubts on our discussion forum as you can. We are all IITians and here to help you in your IIT JEE preparation. Win exciting gifts by answering the questions on Discussion Forum..
GOODLUCK
Please feel free to post as many doubts on our discussion forum as you can. We are all IITians and here to help you in your IIT JEE preparation. Win exciting gifts by answering the questions on Discussion Forum..
Please feel free to post as many doubts on our discussion forum as you can. We are all IITians and here to help you in your IIT JEE preparation.
Win exciting gifts by answering the questions on Discussion Forum..
Get your questions answered by the expert for free
You will get reply from our expert in sometime.
We will notify you when Our expert answers your question. To View your Question
Win Gift vouchers upto Rs 500/-
Register Yourself for a FREE Demo Class by Top IITians & Medical Experts Today !