Question

如果x2+x-1=0有两根X1,X2求〖(X1)2-X2-1〗〖（X2）2-X2-1〗的值拜托各位大神

Answer 1

是求[(X1)2-X1-1][（X2）2-X2-1]吧?∵x2+x-1=0有两根X1,X2 ∴(X1)2+X1-1=0,（X2）2-X2+1=0;x1*x2=-1 ∴[(X1)2-X1-1][（X2）2-X2-1] =[(X1)2+x1-1-2X1][（X2）2+x2-1-X2] =(-2x1)(-2x2) =4x1*x2 =-4