Question 539867
The length of the latus rectum for the ellipse (x^2/64) + (y^2/16) = 1 is equal to:
a)2
b)3
c)4
d)5
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Standard form of equation for ellipse with horizontal major axis: 
(x-h)^2/a^2+(y-k)^2/b^2=1,a>b, (h,k)=(x,y) coordinates of center
From given equation, b^2=16
a^2=64
a=8
Formula for length of the latus rectum for the ellipse: 2b^2/a
2b^2/2a=2*16/8=4
ans: c)4