G8. C11.1 Functions

Chapter 11
11.1 Functions

​Objective of the lesson

​In this section you will …

• represent situations in words and using functions.

Apperception

The cost of hiring a hall is in two parts. There is

1. a booking fee of $15

2. a charge of $40 per hour.

Find the cost of hiring the hall for 7 hours!
The cost of hiring the digger for n days is $y
Write a function to find the cost for any number of days.

Fill in the Blanks

Arun buys some books online. The cost is $6 for each book plus postage of $4.

Work out the total cost, including postage, of 3 books!

Answer : $

Fill in the Blanks

Arun buys some books online. The cost is $6 for each book plus postage of $4.

Work out the total cost, including postage, of 6 books!

Answer : $

Draw

Arun buys some books online. The cost is $6 for each book plus postage of $4.

Write a function to show the cost in dollars (c) of b books.

Fill in the Blanks

A plumber comes to a house to do a repair.

He charges a fixed fee of $45 plus $30 per hour.

Work out the total cost for a job that lasts 1.5 hours.

Answer : $

Draw

A plumber comes to a house to do a repair.

He charges a fixed fee of $45 plus $30 per hour.

Write a function to show the cost in dollars (c) of a job that takes h hours.

Multiple Choice

To find the perimeter of a rectangle you add together double the length and double the width.

The length of the rectangle is l and the width is w.

Select the correct formula for the perimeter, P, of the rectangle.

• $$P=2l+w$$

• $$P=2l+2w$$

• $$P=l+2w$$

• $$P=l+w$$

Draw

If p = –2 and q = 3, evaluate  $$\frac{3p}{q}$$

Fill in the Blanks

If y + z = 20 and z = 9, then y =

Fill in the Blanks

There are 2p + 5 counters in the picture.

If there are 25 counters altogether, what is the value of p?

 

Answer : P =

Multiple Choice

Tanesha’s pay for working t hours is calculated using this formula.

$P = 12.5t + 50

Calculate how much Tanesha will be paid if she works 15 hours.

• $ 237.5

• $ 187.5

• $ 257.5

• $ 187.5

Fill in the Blanks

A function is given as p = 24 − 5q.

What is the value of p when q = 2?

p =

Fill in the Blanks

The area of a park can be found using the function A = 5L +12, where L is the length of the park. Hanane measures the length of the park to be 35 m. Work out the area of the park.

Answer :

m²

Fill in the Blanks

Find the perimeter of this rectangle for w = 7.

Perimeter =

 cm

Fill in the Blanks

Using r = 5 and m = 8, find the value of 3r − m.

Answer: 3r − m = _

Fill in the Blanks

Tanesha’s pay for working t hours is calculated using this formula.

$P = 12.5t + 50

Calculate how many hours Tanesha has worked for if she is paid $387.50.

Number of hours =

Fill in the Blanks

A function is given as p = 24 − 5q.

What is the value of q when p = 12?

Answer :

q =

Draw

A function describes the relationship between x and y, where x = 6 and y = 15. Each part of the function contains different single digits.

Enter numbers to complete the function.

Conclusion

Surely, Now i can ....

• represent situations in words and using functions.

Open Ended

Reflection and Self-assessment

https://bit.ly/G8-Tulip