If $23=x^4+\frac{1}{x^4}$, then what is the value of $x^2+\frac{1}{x^2}$?
Hi qwertyzz,
I'm really bad with these problems so this solution is probably wrong, but I'll give it a shot anyway!
If 23=x4+1x4 then what is the value of x2+1x2?
So how I did this is:
First, I just set x2+1x2=y
If you square both sides of x2+1x2=y, you get (a2)2+2a2⋅1a2+(1a2)2=y2.
So, this means that a4+1a4=y2−2.
We know that a4+1a4=23, so y2−2=23
So, we know y=±5
I hope this was right?
Please tell me if this is right!
:)