# Exponential growth

## Lesson details

### Key learning points

1. In this lesson, we will learn about the exponential function and how it relates to powers of n.

### Licence

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## Video

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## Worksheet

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## Starter quiz

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### 5 Questions

Q1.
If y = 2^n, what is the value of y when n = 5?
1
10
2
Q2.
If y = 5^n, what is the value of y when n = -3?
-1/125
-125
125
Q3.
You are given that 6^a < 220 < 6^b and that 'a' and 'b' are consecutive integers. What are the values of 'a' and 'b'?
a = 1, b = 4
a = 2, b = 3
Correct answer: a = 3, b = 4
a = 3, b = 7
Q4.
y = 9^x would cut the y-axis at the coordinate...
(1,0)
y = 1
y = 9
Q5.
y = 2x is an example of an exponential.
True

## Exit quiz

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### 5 Questions

Q1.
Starting with 100 bacteria, how many would there be after 1 hour if the number of bacteria increases by 20% every 12 minutes?
120
248
249
Q2.
Which of the following is the closest approximation to e?
2.7
2.7182
3.14
Q3.
If a bacterium increases by 1% in 2 minutes, would this form an exponential curve?
No
Q4.
What is the coordinate of intersection with the y-axis for y = e^x?