Big Ideas Math Algebra 2, 2014
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Big Ideas Math Algebra 2, 2014 View details
3. Graphing Radical Functions
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Exercise 46 Page 257

Consider all of the possible transformations of radical functions.

g(x)=sqrt(- x+2)

Practice makes perfect

We want to use the given graph to write a rule for g. To do so, let's first identify the transformations that were applied to the parent function f(x)=sqrt(x).

We can see that the graph of g is a reflection in the y-axis followed by a horizontal translation right 2 units. Let's consider how these types of transformations affect the equation of the function.
Transformations of f(x)
Horizontal Translations Translation right h units, h>0 y=f(x- h)
Translation left h units, h>0 y=f(x+ h)
Reflections In the x-axis y=- f(x)
In the y-axis y=f(- x)
Using the table, we can write the transformations of f. Let's start by finding the rule for h, whose graph is a reflection in the y-axis of the graph of f. h(x)=f(-x) ⇔ h(x)=sqrt(-x) Finally, let's write the rule for g, whose graph is a translation right 2 units of the graph of h. g(x)=h(x- 2) ⇔ g(x)=sqrt(- (x- 2)) We can simplify the above formula by using the Distributive Property.
g(x)=sqrt(- (x-2))
g(x)=sqrt(- x+2)
The desired function rule is g(x)=sqrt(- x+2).