Question

If x2 +1/x2 =51 find the value of X-1/x ​

Answer 1

Answer:

(x-1/x)² = x² - 2 + 1/x²

but x²+1/x² = 51

thus, (x-1/x)² = 51 - 2 = 49

therefore, x - 1/x = sqrt (49) = +/-7

x-1/x = +/-7.