Transformations Part 4: 90° Rotations and Their Equations | TMUA

How do you find the equation of a graph after a 90° rotation, especially when the centre isn’t the origin? In Part 4 of the transformations series, we use the shape of a curve and the movement of key points to understand its rotation and find its new equation. We work through four questions covering: • Rotating a parabola about a given point. • Two successive rotations with an unknown centre. • Counting intersections after rotating a modulus graph. • Finding the equation of a rotated cubic. The emphasis is on clear geometric reasoning: understanding what moves where, and connecting the resulting graph to its equation. 0:00 Introduction and basics of 90° rotations 3:01 Question 1: rotating a parabola 5:11 Question 2: two rotations and an unknown centre 9:26 Question 3: counting intersections after rotation 13:15 Question 4: finding the equation of a rotated cubic Free TMUA practice and more resources: https://jzmaths.com If you find the video useful, please consider subscribing. It helps the channel grow and reach more students. Thank you!