Question

If $x^2+1/x^2=38$ find$x-1/x$

• A. 10
• B. 8
• C. 6
• D. 4

Answer 1

Answer:

C. 6

$(x-1/x)^2=x^2+2-1/x^2$

$(x-1/x)^2=x^2+1/x^2-2=38-2=36$

$x-1/x=\sqrt{36}=6$