Pearson Algebra 2 Common Core, 2011
PA
Pearson Algebra 2 Common Core, 2011 View details
10. Normal Distributions
Continue to next subchapter

Exercise 43 Page 745

Make a table of values, plot the obtained points, and connect them with a smooth curve.

Graph:

Conic Section: ellipse centered at (0,0) with foci at (±4,0)
Lines of Symmetry: x=0 and y=0
Domain: - 5 ≤ x ≤ 5
Range: - 3 ≤ y ≤ 3

Practice makes perfect

To graph the given equation, we will make a table of values.

x 9x^2+25y^2=225 y
- 5 9( - 5)^2+25y^2=225 0
- 3 9( - 3)^2+25y^2=225 ± 2.4
0 9( 0)^2+25y^2=225 ± 3
3 9( 3)^2+25y^2=225 ± 2.4
5 9( 5)^2+25y^2=225 0

We will now plot and connect the obtained points with a smooth curve.

Let's describe what we see in this graph.

Extra

Calculating foci
Each ellipse has two foci. We calculate them by using the following formula, with x being the point where the ellipse intersects the x-axis and y being the point where the ellipse intersects the y-axis. (± sqrt(y^2-x^2),0) We have that x= ± 3 and y= ± 5. We can substitute the values into the formula and calculate the foci location.
(± sqrt(y^2-x^2),0)
(± sqrt(( ± 5)^2-( ± 3)^2),0)
(± sqrt(25-9),0)
(± sqrt(16),0)
(± 4,0)