Identify the Y-Intercept

Lesson 9.2

Identify the y-intercept (initial value)

Definition:

y-intercept: The y-intercept, or initial value, is where your line crosses the y-axis. It is commonly represented by the variable "b". Your y-intercept is whatever your y-coordinate is when your x coordinate is 0. Mathematically, (0,b) where b is your y-intercept.

​Visual:

Multiple Choice

What is the y-intercept of the line?

• b = 2

• b = 4

• b = -2

• b = -4

Multiple Choice

What is the y-intercept of the graph?

• b = 2

• b = 1/2

• b = -2

• b = -1/2

​How to find the y-intercept in word problems:

​The y-intercept, or initial value, can be found by looking for the number that is not affected by time. You will be looking for a number that will remain the same regardless of time. The y-intercept will often have a word before it such as "initial, start, began, etc...".

.

You started with $500 in your banking account and you deposit $30 each week.

.

Find the y-intercept:

Multiple Choice

Christina has a garden that started with 100 rose bushes. She plants 2 rose bushes every week.

What is the y-intercept in this problem?

• b = 2

• b = 100

• b = -2

• b = -100

Multiple Choice

Mr. Carbone's class starts with 37 A's. Every week 3 students lose their A's.

What is the y-intercept?

• b = 37

• b = 3

• b = -37

• b = -3

Write the y-intercept as a coordinate:

Multiple Choice

What is the coordinate of the y-intercept?

• (-2,0)

• (0,-2)

• (2,0)

• (0,2)

Match

Match the following

b = 3

b = -3

b = 0

b = -5

Puppy

• b = 3

• b = -3

• b = 0

• b = -5

• Puppy

​Conclusion and Rating:

Two complete sentences about what you learned. Rate yourself 1-4.