Which of the following is the equation of an ellipse centered at (4,-1) having a horizontal minor axis of length 14 and a major axis of length 20?

A. (x-4)^2/100 + (y+1)^2/49=1

B. (x-4)^2/14 + (y+1)^2/20=1

C. (x+1)^2/49 + (y-4)^2/100=1

D. (x-4)^2/49 + (y+1)^2/100=1

Question

Which of the following is the equation of an ellipse centered at (4,-1) having a horizontal minor axis of length 14 and a major axis of length 20?

A. (x-4)^2/100 + (y+1)^2/49=1

B. (x-4)^2/14 + (y+1)^2/20=1

C. (x+1)^2/49 + (y-4)^2/100=1

D. (x-4)^2/49 + (y+1)^2/100=1

anonymous · Answer

attachment

shamil98 · Answer

If you read your study on ellipses you'll remember that
the equation of this is
(x-h)^2/a^2 + (y-k)^2/b^2 = 1
(h,k) are your center coordinates.
major axis = 2a
minor axis = 2b

shamil98 · Answer

2a = 20
a = 10
2b = 14
b = 7
just plug in your given values to get the equation

anonymous · Answer

so the answer would be B. (x-4)^2/49 + (y+1)^2/100=1 ?

shamil98 · Answer

no, its A, remember a^2 is under x

anonymous · Answer

even though the denominators in A are 100 and 49?

shamil98 · Answer

a = 10
b = 7
the formula is 
(x-h)^2/a^2 + (y-k)^2/b^2 = 1
(x-4)^2/100 + (y+1)^2/49 = 1

anonymous · Answer

oh I see! thanks for explaining it :)

shamil98 · Answer

mhm