Question 1087981
Square both sides of each equation:
x^2 = 4cos^2(t) -> x^2/4 = cos^2(t)
y^2 = 9sin^2(t) -> y^2/9 = sin^2(t)
Now add the two equations:
sin^2(t) + cos^2(t) = x^2/4 + y^2/9
x^2/4 + y^2/9 = 1
This is the standard form for an ellipse.