Answer:
The equation of the ellipse is standard form is expressed as:
x²/81 + y²/9 = 1
Explanation:
General equation of an ellipse is expressed as shown below:
x²/a² + y²/b² = 1
Length of the major axis = 2a
Length of the Minor axis = 2b
Given length of major axis = 18
18 = 2a
a = 9
Similarly, if the length of the minor axis is 6, then
6 = 2b
b = 3
The equation of the ellipse becomes;
x²/9² + y²/3² = 1
x²/81 + y²/9 = 1
Finding the LCM
(x²+9y²)/81 = 1
x²+9y² = 81