McGraw Hill Glencoe Algebra 1, 2012
MH
McGraw Hill Glencoe Algebra 1, 2012 View details
1. Square Root Functions
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Exercise 44 Page 625

Practice makes perfect
a We will graph the quadratic function To do so, let's first make a table of values.

Now, we will plot these ordered pairs on a coordinate system and draw a smooth curve that connects them.

Graph of a Quadratic Function
b We will write a piecewise function to describe the graph of in each quadrant. Let's first remember the signs of the and coordinates in each quadrant.
Quadrants
Notice that is defined as the square of in the given function. Since the square of a real number is always non-negative, the value of cannot be negative. Therefore, the given function is not defined in the second and third quadrants. Now, let's find how the function is defined in terms of
Since we have an absolute value equation we will consider two cases — the negative case and the positive case.

Note that the function is defined in the first and forth quadrants where and respectively. We can now write a piecewise-defined function to describe the graph of in the first and forth quadrants.
c We will now graph the square root functions and From Part B, we know that the values of cannot be negative in these functions. With this in mind, let's make a table of values for the function

Now, we will plot these points on the same coordinate system as Part A and connect them with a smooth curve.

Graphs of Quadratic and Square Root Functions

We will apply the same procedure to graph the function Let's make a table of values.

Let's plot these points on the same coordinate system and draw a smooth curve connecting them.

Graphs of Quadratic and Square Root Functions
d We will continue by drawing the graph of on the same coordinate system. To do this we will follow the same procedure as we did in Part C.

Let's draw the line passing through these points.

Graphs of Quadratic and Square Root Functions

Now let's plot the points and

Comparing Graphs of Quadratic and Square Root Functions
e From the graph in Part D, we can observe that if we switch the coordinates of any ordered pair on the parabola we get a point on one of the square root functions. It means that the graph of the parabola and the graphs of the square root functions are symmetric about the line
Comparing Graphs of Quadratic and Square Root Functions