Question

if x square + 4x-1=0 and x is a positive then find the value of x+1/x​

Answer 1

Answer:

Step-by-step explanation:

$x^2+4.x-1 =0\\x^2-1 = -4x$

dividing both sides by x:

$x-1/x = -4\\Now\\\{(x+1/x)}^2 = {(x-1/x)}^2 +4\\{(x+1/x)}^2 = 16+4 = 20\\x+1/x = \sqrt20 = 2\sqrt5$