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
If a is a root of 4x²+2x-1=0, then the other root is
1)3a³-4a 2) 4a³-3a 3) 3a³+4a
4) 4a³+3a
Let the other root be b.
According to the quadratic equation theory,
sum of roots=-(B/A)
so,a+b=-2/4=-1/2
b=-1/2a
I suggest you to check your question and post it again.
Hope that works.
Hi Sudhanshu,
Note that the roots of this equation are {root(5)-1}/4 ------- which is cos72
and -{root(5)+1}/4 -----------which is -cos36.
Now -cos36 = cos(36+180) = cos(216) = cos(3*72)
Now cos3x = 4cos^3 x - 3cosx....
So if one root is "a" (=cos72), then the other root is 4a^3-3a..... and that would be option (2).
Best Regards,
Ashwin (IIT Madras).
Register Yourself for a FREE Demo Class by Top IITians & Medical Experts Today !