Pearson Algebra 2 Common Core, 2011
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Pearson Algebra 2 Common Core, 2011 View details
4. Ellipses
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Exercise 35 Page 642

Practice makes perfect
a

Let's recall the properties of an ellipse with center (0,0).

Properties of Horizontal Ellipses

Standard Equation x^2/a^2+y^2/b^2=1 a> b>0

Major Axis

Horizontal

Vertices

(± a,0)

Co-vertices

(0,± b)

Foci

(± c,0) on x-axis

Properties of Vertical Ellipses

Standard Equation x^2/b^2+y^2/a^2=1 a> b>0

Major Axis

Vertical

Vertices

(0,± a)

Co-vertices

(± b,0)

Foci

(0, ± c) on y-axis

We can see that the given ellipse is a horizontal ellipse. The hole and tee are located at the foci, (± c,0). Therefore, the distance between them will be equal to the value of 2c. To determine the value of c, we first need to find a and b. The length of the major axis is 2a, and the length of the minor axis is 2b. Let's identify the values of a and b.

Major Axis Length=2a
24=2a
12=a

We have identified the value a= 12. Let's identify the value of b.

Minor Axis Length=2b
9=2b
4.5=b

Now that we have the values of a and b, we can use the fact c^2=a^2-b^2 for an ellipse to determine the value of c.

c^2=a^2-b^2
c^2= 12^2- 4.5^2
c^2=144-20.25
c^2=123.75
sqrt(c^2)=sqrt(123.75)
c ≈ 11.124

Finally, using the value of c= 11.124, we can determine the distance between the hole and tee. Distance=2 c ⇕ 2( 11.124) ≈ 22.25 feet

b

The definition of an ellipse is a circle stretched in one direction with a set of points that have a total fixed distance from two points. Because of this, ellipses have a reflective property. Aiming the putt at any point of the ellipse border will directly go to the hole.