There's a few, but anything would help me!

3. sketch the graph of the quadratic function using the vertex, y-intercept, and symmetric point.

a.vertex: (-1,4) and y-intercept: 7

b. Vertex: (-3, -4) and y-intercept : 0

4. Find tgr orderd pair of the vertex using either algebraic method (vertex form or the folmula drived from the Quadratic formula)
a. y=x^2-8x+15

b. y=-3x^2-1x-15

2. Originally Posted by Kayla
There's a few, but anything would help me!

3. sketch the graph of the quadratic function using the vertex, y-intercept, and symmetric point.

a.vertex: (-1,4) and y-intercept: 7
Plot the point (-1,4) in your x-y plane. Then plot 7 on the y-intercept.

Now join the point to the y-intercept.

Originally Posted by Kayla
4. Find tgr orderd pair of the vertex using either algebraic method (vertex form or the folmula drived from the Quadratic formula)
a. y=x^2-8x+15
You need to complete the square here, i'll do the first one, you can try the second.

$\displaystyle y=x^2-8x+15$

Take the coefficent of x , half it then square it to give a new constant term.

$\displaystyle y=\left(x^2-8x+\left(\frac{-8}{2}\right)^2\right) +15-16$

$\displaystyle y=\left(x^2-8x+16\right)-1$

$\displaystyle y=(x-4)^2-1$

giving a vertex of $\displaystyle (4,-1)$

3. I need the most help with y=-3x^2-12x-7 because of the -3x^2, My teacher tried to tell me to divide by -3, I still do not understand.

4. $\displaystyle y=-3x^2-12x-7 = -3\left(x^2+4x+\frac{7}{3} \right)$

Now complete the square as shown previously inside the brackets.