A parabola with a vertical axis has its vertex at the origin and passes through point (7,7).The parabola intersects line y=6 at two points.The length of the segment joining these points is
A) 14
B) 13
C) 12
D) 8.6
E) 6.5

Question

​A parabola with a vertical axis has its vertex at
the origin and passes through point (7,7) The parabola intersects
line y=6 at two points The length of the segment joining these
points is
A) 14
B) 13
C) 12
D) 8 6
E) 6 5

Lovina Kansal · Accepted Answer

Dear student
The equation of a vertical parabola with its vertex at the originhas the form y=ax2 
(1)Substitue (7,7) for x and y,we get7=a(7)2⇒a=17When y=6,then (1) becomes6=17x2⇒x2=42⇒x=±42So, the length of segment=2x=242≈13 units
Regards

​A parabola with a vertical axis has its vertex at the origin and passes through point (7,7).The parabola intersects line y=6 at two points.The length of the segment joining these points is A) 14 B) 13 C) 12 D) 8.6 E) 6.5

A parabola with a vertical axis has its vertex at the origin and passes through point (7,7).The parabola intersects line y=6 at two points.The length of the segment joining these points is
A) 14
B) 13
C) 12
D) 8.6
E) 6.5