Find the standard form of the equation of the ellipse with the given characteristics. vertices: (- 2, 2), (- 2, 16) minor axis of length 8
ANSWER CHOICES: (x-2)^2/16+(y+9)^2/49=1 (x+2)^2/16+(y-9)^2/49=1 (x+2)^2/49+(y-9)^2/16=1 (x-9)^2/49+(y+2)^2/16=1 (x+9)^2/49+(y-2)^2/16=1
The length of the major axis is 2a. The length of the minor axis is 2b. The center is at the midpoint of the major axis.
Use that information to find a, b and the center (h,k) and plug into this equation: \[\frac{(x-h)^2}{a^2}+\frac{(y-k)^2}{b^2}=1\]
notice the vertices of the ellipse (-2, 2) and (-2, 16) notice the x-coordinate doesn't change, but the y-coordinate does that means the ellipse major axis is the y-axis, or is "vertical" keep in mind that center of the ellipse, is half-way between the vertices half-way between (-2, 2) and (-2, 16), let's use the midpoint formula for kicks :) \(\bf \left(\cfrac{(-2)+(-2)}{2}, \cfrac{(2)+(16)}{2}\right) \implies (-2, 9)\) so the center is at (-2, 9) the distance from the center to either vertex is "a" over the "y" is moved from (-2, 2 ) to (-2, 9), that is 7 units thus a = 7 the minor axis is given, that is, 8 units, thus b = 8 so (h, k) = (-2, 9) # center a = 7 # major axis unit b = 8 # minor axis uniit see above as Mertsj showed, the equation for the ellipse, and put your values in :)
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