Every time a number is entered into a function
machine, a different number comes out. If 6 goes
in, 2 comes out. If 12 goes in, 4 comes out. If 15
goes in, 5 comes out. Which function is performed
in the machine?
Answers
Answer:
Finding the Output
Look at the function machine below:
4
× 5
?
To work out the output, we need to take the input and multiply by 5. This gives an output of 20.
Now look at the double function machine below:
5
× 2
- 1
?
This time, we need to multiply the input by 2 and then subtract 1. This gives an output of 9.
Practice Questions
Work out the output from these two function machines, then click Click on this button below to see the correct answer to see whether you are correct.
12
÷ 4
?
7
- 3
× 2
?
Finding the Input
Sometimes we will be given the output from a function machine and we need to work out the input.
To do this, we work backwards through the machine, doing the inverse operation at each stage.
Look at the function machine below:
?
× 4
8
To work out the input, we need to take the output and divide by 4 (the opposite of multiplying by 4).
This gives an input of 2.
Now look at the double function machine below:
?
- 5
× 3
6
This time, we need to do the inverse operations from right to left. We divide the output by 3 and then add 5.
This gives an input of 7.
Inverse Operations
The table below shows the inverse (i.e. opposite) operations.
Practice Questions
Work out the input to these two function machines, then click Click on this button below to see the correct answer to see whether you are correct.
?
÷ 3
3
?
+ 2
× 5
25
Step-by-step explanation:
please mark me as a brainlist please