log2(x²)=log2[(√2-1)/(√2+1)]log2(x²)=log2(√2-1)²所以x²=(√2-1)²x=±(√2-1)x=√2-1则1/x=√2+1x+1/x=2√2x=-√2+1则1/x=-√2-1x+1/x=-2√2所以x+1/x=±2√2