CPM Homework Help : A2C Problem 4-121

For each equation below, find the x- and y-intercepts and the locator point (h, k), then write the equations in graphing form. Homework Help ✎
1. y = 7 + 2x² + 4x − 5
2. x² = 2x + x(2x − 4) + y

Hint (a):

y-intercept: y = 7 + 2(0)² + 4(0) − 5

Hint 2 (a):

You will need to factor. There is only one x-intercept.

x-intercept: 0 = 7 + 2x² + 4x − 5

More Help (a):

Since there is only one x-intercept, the vertex must be at the x-intercept. To find the equation in graphing form, use the equation y = a(x − h)² +k.

Answer (a):

y-intercept: (0, 2)
x-intercept: (−1, 0)
vertex: (−1, 0)
y = 2(x + 1)²

Hint (b):

Start by finding the x- and y-intercepts.

Hint 2 (b):

To find the x-coordinate of the vertex, average the x-intercepts.

To find the y-coordinate of the vertex, substitute the x-coordinate of the vertex into the given equation and solve for y.

More Help (b):

Now write the equation in graphing form.