please help!!

find the set for "m" so that the graphs of y=mx and y=(x^2)+m intersect in a single point.

- Sep 5th 2007, 06:20 PMginax7Find the set for "m" so that the graphs of y=mx and y=x^2+m intersect a single poi
please help!!

find the set for "m" so that the graphs of y=mx and y=(x^2)+m intersect in a single point.

- Sep 5th 2007, 06:27 PMKrizalid
First, we gotta set and , now set

The discriminant of this must be zero (such that and intersect in a single point), so

- Sep 5th 2007, 06:28 PMtopsquark
ginax7,

*please*consider using a different colored font. You know, black really is an acceptable color for typing. Really! :D

Quote:

Find the set for "m" so that the graphs of y = mx and y = (x^2)+m intersect in a single point.

This must have only one solution, so the discriminant must be 0:

So either m = 0 or m = 4.

-Dan - Sep 5th 2007, 06:32 PMginax7thanks
thanks guys! sorry bout the pinkness! It's the first day of school and I havent even learned about discriminants I dunno why hes giving us problems like these :(

- Sep 5th 2007, 06:38 PMKrizalid
Suppose you have the following quadratic equation

The following formula solves this equation

The expression it's called__discriminant__, which says who rules here! :)

If , then the equation has two real and different roots.

If , the the equation has two real and equal roots

If , the equation has two complex roots.

Hope it helps :)