The graphs that represent a linear function and a quadratic function are shown here.

Graph of a linear function and a quadratic function. Line with points at 0 comma 5 and 2 point 5 comma 0. Parabola intersects the line at point R and intersects the x axis at 0 and 2 point 5

The quadratic function is defined by .

Find the coordinates of point  without using graphing technology. Show your reasoning.

Diego finds his neighbor's baseball in his yard, about 10 feet away from a five-foot fence. He wants to return the ball to his neighbors, so he tosses the baseball in the direction of the fence.

Function , defined by , gives the height of the ball as a function of the horizontal distance away from Diego.

Does the ball clear the fence? Explain or show your reasoning.

Clare says, “I know that is an irrational number because its decimal never terminates or forms a repeating pattern. I also know that is a rational number because its decimal forms a repeating pattern. But I don’t know how to add or multiply these decimals, so I am not sure if and are rational or irrational."

1. Here is an argument that explains why is irrational. Complete the missing parts of the argument.

   1. Let . If were rational, then would also be rational because . . . .
   2. But is not rational because . . . .
   3. Since is not rational, it must be . . . .
2. Use the same type of argument to explain why is irrational.

The following expressions all define the same quadratic function.

1. What is the -intercept of the graph of the function?
2. What are the -intercepts of the graph?
3. What is the vertex of the graph?
4. Sketch a graph of the quadratic function without using technology. Make sure the -intercepts, -intercept, and vertex are plotted accurately.

Here are two quadratic functions:  and .

Andre says that both  and have a minimum value, and that the minimum value of is less than that of . Do you agree? Explain your reasoning.

Without using graphing technology, sketch a graph that represents each quadratic function. Make sure the vertices and any intercepts that fit on the given grids are plotted accurately.