若X=19/√19+8√3 则分式X^4-6X^3-2X^2+18X+23\X^2-8X+15

问题描述:

若X=19/√19+8√3 则分式X^4-6X^3-2X^2+18X+23\X^2-8X+15

你这题显然,打错了已知条件建议改为x=13/√(19+8√3)=13/√(4+√3)^2=13/(4+√3)=4-√34-x=√3两边平方 x^2-8x+13=0(X^4-6X^3-2X^2+18X+23)/(X^2-8X+15)=x^2+2x-1-(20x-38)/(x^2-8x+13+2)=x^2-8x+18=x^2-8x+13+5=5...