Algebra2 ( Check)
posted by Anonymous .
Will you please check my work for me.
1)The equation of a parabola is shown.
y=1/14X^2. What are the coordinates of the focus?
(0,3.5) <
(0,4)
(0,7)
2)The equation x2 + (y + 3)2 = 36 models the boundary on a local map for which Darren can hear his friend Tom on his twoway radio when Darren is at home. How far (in miles) can Tom walk from Darren's home and still be heard?
3 miles
6 miles<
2 miles
12 miles
3)A plane intersects only one nappe of a doublenapped cone. It is neither perpendicular to the cone's axis nor parallel to its generating line. Which conic section is formed?
point
circle
ellipse <
parabola

1. Y = (1/14)x^2.
V(h,k)
h = Xv = b/2a = 0 / (1/7) = o.
k = Yv = (1/14)*0^2 = 0.
4a = 4(1/14) = 4/14 = 2/7.
1/4a = 7/2.
V(0,0), F(0,y).
VF = y0 = 1/4a = 7/2
y0 = 7/2
Y = 7/2 = 3.5.
F(0,3.5).