Suppose a parabola has an axis of symmetry at x = –7 , a maximum height of 4 and also passes through the point (–6, 0). Write the equation of the parabola in vertex form.

Question

Suppose a parabola has an axis of symmetry at x = –7  , a maximum height of 4 and also passes through the point (–6, 0). Write the equation of the parabola in vertex form.

divinesolar · Answer

Please post in the Mathematics section not English. @PrincessBee

anonymous · Answer

Oh haha!! Oops sorry! Kind of new to this!

divinesolar · Answer

@PrincessBee Anyways i will help you with this one but anyways here is the answer. The vertex form of the equation is y = a(x - h)2 + k  

Since the vertex is defined as (h, k), h = -7 and k = 4:

y = a(x - (-7))2 + 4   or:  y = a(x + 7)2 + 4 

We just need to find the value of "a" (which must be negative, remember, it opens down).  Here is where we use the point through which the parabola passes through: (-6, 0).

We substitute the values x = -6, y = 0 in the equation and solve for a:

0 = a(-6 + 7)2 + 4      simplify and subtract 4 on both sides of the equation:

-4 = a(1)2     or  a = -4  Now we are ready to write our completed equation:

y = -4(x + 7)2 + 4 
Medal if this helped.

anonymous · Answer

So y=-4(x+7)2+4 is the answer!?

divinesolar · Answer

Yes.

divinesolar · Answer

Medal? Did i help :D?

divinesolar · Answer

If you dont know how to do that then you click best response to the right of my name. @PrincessBee