# Part 2

- Author:
- Sidney Scott

**Displayed is the unit circle.**

## Question 1

A. What is the center of the unit circle? B. What is the length of its radius? C. What are the x-intercepts? D. What are the y-intercepts? E. What is the formula given under the conic section (to the left of the graph) for the unit circle?

**Manipulate the red slider ('r') and observe the results.**

## Question 2

A. What happens to the red circle as the value of 'r' increases and decreases? B. What kind of relationship do they have?

**Adjust slider so that r=1.**

## Question 3

What value does the equation of circle 'c' equal?

**Adjust slider so that r=2.**

## Question 4

What value does the equation of circle 'c' equal?

**Adjust slider so that r=3.**

## Question 5

What value does the equation of circle 'c' equal?

**Adjust slider so that r=4.**

## Question 6

What value does the equation of circle 'c' equal?

**Adjust slider so that r=5.**

## Question 7

What value does the equation of circle 'c' equal?

## Question 8

## Question 9

Notice how the graph plotted looks similar to a graph we have seen before. Which function does it resemble?

## Question 10

What relationship do the values in the 'r' column have to the column?

## Question 11

Based on the pattern you found in table, what is the general form for the formula of a circle with the center at A = (0,0)?

**Once you have answered all the questions in Part 2, you may move on to Part 3.**