# Maths Video Lesson 5 Revision eNotes

# Contents

Contents 2

Lesson 5-Real Life quadratic graphs 4

Free Maths Tutorial 4

Example 1 4

Example 2 6

Perimeter and Area 7

Example 3 8

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Lesson 5-Real Life quadratic graphs

## Free Maths Tutorial

These revision notes have been brought to you by an experienced Maths teacher - Mr Tom Nolan. These notes can be read in conjunction with the Free maths tutorial linked below. You will find this tutorial under iRevise.com, junior cert, maths, videos. These notes are suitable for Junior Certificate Students and covers Linear Maths. There is a work sheet and solutions that are an add on to the notes and can also be purchased from iRevise.com.

## Example 1

The height reached by a rocket fired from level ground is given by the equation.

F(X) =

(i) Graph this function in the domain 2 ≤ X ≤ 5

(ii) What is the highest point reached.

(iii) At what time is the rocket 9m above the ground.

(iv) For how long is the rocket 5m above the ground.

(i)

X= | -2 | -1 | 0 | 1 | 2 | 3 | 4 | 5 |

10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 |

+8X | -16 | -8 | 0 | 8 | 16 | 24 | 32 | 40 |

-2X² | -8 | -2 | 0 | -2 | -8 | -18 | -32 | -50 |

Y | -14 | 0 | 10 | 16 | 18 | 16 | 10 | 0 |

(ii) Highest Point = (2,18)

(iii) 9m above the ground, after .9min and 5.2 mins.

(iv)How long is it 5m above the ground. From .5 min to 5.5min.

## Example 2

The formula for the height, Y metres, of a ball above the ground level, x seconds after it is fired vertically into the air, is given by Y= 35x – 5x².

Use your graph to estimate in domain 0 ≤ x ≤ 4

(i) Maximum height reached by the ball.

(ii)Height of the bal...