Question

if x=1/2root7, then find the value of x^2-x/2root7

Answer 1

x + 1 x = 7
⇒ (x + 1 x )2 =(7)2
⇒ (x2+ 1 x 2 + 2) = 49
⇒ x2+ 1 x 2 = 47

Therefore, x2+ 1 x 2 = 47.

Answer 2

If x = 1/2root7-----------{eq1}
Then x^2 = (1/2root7)^2
= 1/28---------eq2
Then .. we divide the eq1 by 2root 7
=> x / (2root7) = ( 1/2root 7 ) ÷ 2root 7
=> x/ 2root 7 = 1/28 -----------eq3
A.T.Q
From eq 2 and 3
1/28 - 1/28
= 0