Hey can someone please help me

The vertex is located at (h,k)

The two roots p and q can be defined as such

where r is the horizontal distance between the vertex and either root. We use the same r value for each equation because of symmetry. The diagram below shows what I mean.

Let's add up those two equations to get

p+q = 2h

The left hand sides p and q add to p+q. The right hand sides add to (h-r)+(h+r) = 2h. Note the r's cancel.

From here, we divide both sides by 2 and we end up with

h = (p+q)/2

In short, if we know the roots p and q, then we find the x coordinate of the vertex (h) to be the average of those roots. You add up the roots and then divide by 2.

After you figure out the value of h, finding the value of k will have us plug in this h value into the quadratic equation and simplifying.

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Example:

Let's say we have the quadratic y = x^2 - 8x + 12. This factors to (x-2)(x-6)

Solving (x-2)(x-6) = 0 shows that x-2 = 0 becomes x = 2 and x-6=0 becomes x = 6.

So the roots here are p = 2 and q = 6. The order of the roots doesn't matter.

Averaging these roots gives us

h = (p+q)/2

h = (2+6)/2

h = 8/2

h = 4

The x coordinate of the vertex is x = 4.

Plug this back into the original equation to find...

y = x^2 - 8x + 12

y = (4)^2 - 8(4) + 12

y = 16 - 32 + 12

y = -16 + 12

y = -4

Or you could say

y = x^2 - 8x + 12

y = (x-2)(x-6)

y = (4-2)*(4-6)

y = (2)*(-2)

y = -4

Either way, we find that k = -4 is the y coordinate of the vertex

The vertex for this example is located at (h,k) = (4, -4)

Refer to the diagram below.

3. parallelogram

step-by-step explanation:

we turn each of our sides into direction vectors

ab=b-a=(3 - 7, 1 - 0) = (-4, 1)

bc=c-b=(1,6)

cd=d-c=(4,-1)

da=a-d=(-1,-6)

we see how the opposite sides have negated direction vectors; this is characteristic of a parallelogram.   we have congruent sides ab=cd and bc=da with unequal lengths because 1^2+6^2 is different from (-4)^2+1^2.   so it's not a square or a rhombus.  

we check the dot product of direction vectors of adjacent sides.   we have

ab dot bc = -4(1) + 1(6) = 2

that's not zero so the sides are not perpendicular.   we've ruled out rectangle.

the direction vectors indicate two pairs of congruent parallel sides, so we choose parallelogram over trapezoid.

- (2, -7)

- lines r and s and lines t and u must be parallel