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How many times does the graph of the function below intersect or touch the x axis? y=-3x^2+x+4​

User Dutzi
by
5.4k points

1 Answer

5 votes

Answer: Two times.

Explanation:

The graph touches the x-axis when the value of "y" is zero.

Then, substitute
y=0 into the function:


0=-3x^2+x+4

Use the Quadratic formula to solve for "x":


x=(-b\±√(b^2-4ac))/(2a)

You can identify that:


a=-3\\b=1\\c=4

Then, you can substitute values into the Quadratic formula
x=(-b\±√(b^2-4ac))/(2a), so you get:


x=(-1\±√(1^2-4(-3)(4)))/(2(-3))\\\\x_1=(4)/(3)\\\\x_2=-1

Therefore, the graph of this function touches the x-axis two times.

User Steph M
by
5.5k points
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