McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
1. Graphing Quadratic Functions
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Exercise 24 Page 100

Make a table of values and connect the obtained points with a parabola.

Graph:

Domain: All real numbers
Range: y≥ -13

Practice makes perfect

We want to graph the given quadratic function. y=2x^2-8x-5 To do so, we will make a table of values.

x 2x^2-8x-5 y=2x^2-8x-5
-1 2( -1)^2-8( -1)-5 5
0 2( 0)^2-8( 0)-5 -5
2 2( 2)^2-8( 2)-5 -13
4 2( 4)^2-8( 4)-5 -5
5 2( 5)^2-8( 5)-5 5

Let's now plot the obtained points on the coordinate plane and connect them with a parabola.

We see above that the x-variable can take any value. Conversely, the y-variable only takes values greater than or equal to -13. Using this information, we can write the domain and range of the function.

Domain:& all real numbers Range:& y≥ -13