Core Connections Algebra 2, 2013
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Core Connections Algebra 2, 2013 View details
1. Section 4.1
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Exercise 22 Page 176

Create functions of the left-hand side and right-hand side, and enter them into a graphing calculator.

x=1 and x=6, see solution.

Practice makes perfect

To solve this equation graphically we will treat each side as a separate function. (x-3)^2-2= x+1 ⇓ f(x)= (x-3)^2-2, g(x)= x+1

Graphing the Functions

To find the points of intersection we will graph the functions. The x-coordinates are the solutions to the original equation. Pull out your graphing calculator, push Y=, and write the functions in the first two rows.

Window with inequality

By pushing GRAPH the calculator will draw the functions in a coordinate plane.

Window with a graph

Finding the Intersections

To find the points of intersection, push 2nd and then TRACE. This opens a menu where we choose intersect.

Having picked intersect, choose the first and second curve and pick a best guess for the point of intersection. After accepting the three questions, the coordinates of the intersection will be shown at the bottom.

Since we are only interested in the x-values, the solution to the equation is x=1. To find the second solution we repeat the procedure, but this time placing the cursor closer to the second point of intersection.

The second solution is x=6

Alternative Solution

Second Approach

We can also choose to solve the equations by moving all of the terms to one side of the equation. (x-3)^2-2=x+1 ⇕ (x-3)^2-x-3=0 With the new equation, we only have to graph one function and identify where it crosses the x-axis, which will be the zeros of the function. Let's use our graphing calculator again.

Window with inequality
Window with a graph

The zeros can now be found by pushing 2nd and then TRACE. A menu will appear where we should choose the option zero.

Having picked zero, choose the left-bound and right-bound such that this interval includes the zero we wish to calculate.

The first zero is x=1. To find the second zero, we will repeat the process but making sure that the boundaries includes the second zero.

We got the same solutions using both approaches.