What is the equation of a parabola that has a vertex at ( 0,4 ) and passes through points ( 2,0 )?

y = -x² + 4

Step-by-step explanation:

The equation of the parabola in the vertex form is:

y = a (x-h)² + k

Where: (h,k) the coordinates of the vertex & a is a multiplier

The parabola has a vertex at ( 0,4 )

So, h = 0 , k = 4

∴ y = a (x-0)² + 4

∴ y = a x² + 4

The parabola passes through points ( 2,0 )

∴ 0 = a 2² + 4

∴ 4 a = -4  ⇒ a = -4/4 = -1

∴ y = -x² + 4

So, the equation of a parabola that has a vertex at ( 0,4 ) and passes through points ( 2,0 ) is y = -x² + 4

See the attached figure.

this doesn't make sense lol

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,