a&b=a+1/ba%b=b+1/a先已知（2%x）&x=7/2求x^2+1/x^2和x-1/x

Question

a&b=a+1/b a%b=b+1/a先已知（2%x）&x=7/2求x^2+1/x^2 和 x-1/x

Answer 1

a&b=a+1/b a%b=b+1/a （2%x）&x=（2%x）+1/x=x+1/2+1/x=7/2 x+1/x=7/2-1/2=3 (x+1/x)=9 x+2+1/x=9 x+1/x=7 x-2+1/x=5 （x-1/x）=5 x-1/x=±√5