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Re: Does the curve h(x)=y=ax^2+b intersects the x-axis?
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31 Jul 2017, 16:53

Hi,

Question :

Does the curve h(x)=y=ax^2+b intersects the x-axis?

Basically its a parabola equation.

For any parabola, ax2 + bx + C = 0, it will intersect the x axis only if discriminant b2-4ac = 0.

it wont intersect x axis if b2- 4ac<0;

Coming to the question:

y = ax2 + b dicriminant = -4ab ; now our aim is to check whether -4ab (discriminant in the given equation) is less than, equal or greater than 0. 1) h(4)>0 = > 16a+b>0 = >from this we cannot say about a & b we dont know whether a and b is + ve or -ve.

So insuff

2) a>0 so we now have a(>0), but we dont know the value of b.