Asked by Chris Cook
Find m if the line y=mx−2 intersects y=x^2 in just one point.
Answers
Answered by
Steve
you want the solution to
mx-2 = x^2
to have a zero discriminant. So, since
x^2 - mx + 2 = 0
has discriminant of
m^2 - 8
I guess that tells you what m is, right? Take a look at
http://www.wolframalpha.com/input/?i=plot+y%3Dx^2,+y%3D%E2%88%9A8+x-2,+y%3D-%E2%88%9A8+x-2
mx-2 = x^2
to have a zero discriminant. So, since
x^2 - mx + 2 = 0
has discriminant of
m^2 - 8
I guess that tells you what m is, right? Take a look at
http://www.wolframalpha.com/input/?i=plot+y%3Dx^2,+y%3D%E2%88%9A8+x-2,+y%3D-%E2%88%9A8+x-2
Answered by
,,d,,
m is equal to plus or minus sqrt8