x-1/x=2x²-2+1/x²=4x²+1/x²=6x²+2+1/x²=8(x+1/x)²=8x+1/x=±2√2
x-1/x=2x^2-2x-1=0x=1±√2x+1/x=1+√2+1/(1+√2)=2√2x+1/x=1-√2+1/(1-√2)=-2√2x+1/x=±2√2
(x+1/x)^2 = (x-1/x)^2+4 = 2^2+4 = 8x+1/x = ±√8 = ±2√2
x-1/x=2(x-1/x)^2=4(x+1/x)^2=8x+1/x=±2√2