Is the answer[math] \sqrt{\smash[b]{221}}[/math]?Hint: Find the relationship between squares of [imath]x+\frac{1}{x}[/imath] and [imath]\frac{1}{x}-x[/imath] .
square root a?@egal If [imath]x^2=a[/imath] then the value of [imath]x[/imath] is _____?
oh! thanks a lot!@egal [imath]x_{1,2}=\pm \sqrt{a}[/imath]