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
cos20 cos40 cos80= 1/8
l.h.s. :
cos20 cos40 cos80
multiply nd divide by 2
1/2 (2 cos20 cos40 cos80)
1/2 (cos(20+80)+ cos(20-80)) cos40 (2cosa cosb= cos(a+b) + cos(a-b))
1/2 (cos(-60)+ cos(100)) cos40
1/2 (1/2 + cos100)cos40
1/4 cos40+ 1/2 (cos40 cos100)
multiplt nd divide by 2
2/2(1/4 cos40) + 1/4 (2 cos40 cos100)
1/4 cos40+ 1/4 (cos140+ cos(-60)) (2cosa cosb= cos(a+b) cos(a-b))
1/4 cos40+ 1/4 cos140 + 1/8 (cos60= 1/2)
1/4 (cos40+cos140) + 1/8
1/4(2 cos90 cos(-50)) + 1/8 (as above identity)
cos90= 0
1/8
= r.h.s
Register Yourself for a FREE Demo Class by Top IITians & Medical Experts Today !