Question

l1:(2m^2+m-3)x+(m^2-m)y=2m直线L2:x-y=1当m取何值时两直线垂直

Answer 1

L2

y=x-1

斜率=1

垂直则L1斜率=-1

L1

y=-(2m²+m-3)/(m²-m) x+2m/(m²-m)

-(2m²+m-3)/(m²-m)=-1

2m²+m-3=m²-m

m²+2m-3=0

m=1,m=-3

m=1时分母m²-m=0

所以m=-3