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Make sure the equation is written in standard form. Identify the related function and graph it.
Graph:
Solutions: 0, 4
We are asked to solve the given quadratic equation. We will solve it by graphing. To solve a quadratic equation by graphing, we have to follow three steps.
To draw the graph of the related function written in standard form, we must start by identifying the values of a, b, and c. f(x)=2x^2-8x ⇕ f(x)= 2x^2+( - 8)x+ 0 We can see that a= 2, b= - 8, and c= 0. Now, we will follow three steps to graph the function.
Next, we will make a table of values using x-values around the axis of symmetry x=2.
x | 2x^2-8x | f(x) |
---|---|---|
- 2 | 2( - 2)^2-8( - 2) | 24 |
0 | 2( 0)^2-8( 0) | 0 |
2 | 2( 2)^2-8( 2) | - 8 |
4 | 2( 4)^2-8( 4) | 0 |
6 | 2( 6)^2-8( 6) | 24 |
We can finally draw the graph of the function. Since a= 2, which is positive, the parabola will open upwards. Let's connect the points with a smooth curve.
Let's identify the x-intercepts of the graph of the related function.
We can see that the parabola intersects the x-axis twice. The points of intersection are ( 0,0) and ( 4,0). Therefore, the equation 2x^2-8x=0 has two solutions, x= 0 and x= 4.