The Earth’s path around the Sun is elliptical, and the Sun is situated at one of the foci. If the Earth’s orbit can be represented by x^2/25 + y^2/16 = 1, where x and y are measured in 100 million miles, what is the distance from the center of Earth’s elliptical path to the sun?

A.)100 million miles
B.)200 million miles
C.)300 million miles
D.)400 million miles

Question

The Earth’s path around the Sun is elliptical, and the Sun is situated at one of the foci. If the Earth’s orbit can be represented by x^2/25 + y^2/16 = 1, where x and y are measured in 100 million miles, what is the distance from the center of Earth’s elliptical path to the sun? 

A.)100 million miles
B.)200 million miles
C.)300 million miles
D.)400 million miles

anonymous · Answer

theyre looking for the distance from the center of the given ellipse to one of your foci...
since c^2 = a^2 - b^2
where a=5, b=4
can you find c and answer the question?

anonymous · Answer

but that gave me 1,681

anonymous · Answer

c^2 = a^2 - b^2
c^2 = 25 - 16
c^2 = 9

c = ???

anonymous · Answer

Ohh I added, that's where I went wrong, but c=81

anonymous · Answer

no trye agen

anonymous · Answer

c = 3
3*100 million miles = 300 million miles?

anonymous · Answer

yes... you got it... :)