Question

已知实数a,b满足a²-7a+2=0,b²-7a+2=0,求a分之b+b分之a的值

Answer 1

已知实数a,b满足a²-7a+2=0,b²-7b+2=0,求a分之b+b分之a的值

由题意可知,a,b 是方程x² -7x +2=0 的两根,

a+b =7,

ab=2

所以b/a +a/b =(a²+b²)/ab=[(a+b)² -2ab]/ab =(49 -4)/2=45/2