To model the path of Apollo 8 as it orbited the moon, we need to account for both the radius of the moon and the altitude at which Apollo 8 orbited.
- The radius of the moon is given as 1,737 km.
- Apollo 8's average altitude was 185 km above the moon's surface.
To find the total distance from the center of the moon to Apollo 8, we add the altitude to the radius of the moon:
\[ \text{Total radius} = \text{Radius of the moon} + \text{Altitude} = 1,737 , \text{km} + 185 , \text{km} = 1,922 , \text{km} \]
The equation of a circle in the coordinate plane with center at the origin is given by:
\[ x^2 + y^2 = r^2 \]
where \( r \) is the radius of the circle. In this case, we have:
\[ r = 1,922 , \text{km} \]
Now we can calculate \( r^2 \):
\[ r^2 = (1,922)^2 = 3,694,084 \]
Thus, the equation that models the path of Apollo 8 is:
\[ x^2 + y^2 = 3,694,084 \]
So the correct response is:
x squared plus y squared equals 3,694,084.