Completing the square maths GCSE - negative or positive point?
Hi, I'm very confused on an aspect about completing the square.
When you are finding the minimum of the graph/equation, are the y and x values negative or positive, and vice versa for finding the maximum.
Any help would be appreciated thank you.
- PuzzlingLv 71 month agoFavourite answer
The sign of the coefficient on the x² term tells you the type of parabola:
- if 'a' is positive (like y = 3x²), then you have an upward-facing parabola and the vertex is a *minimum* with the rest of the graph above it.
- if 'a' is negative (like y = -3x²), then you have a downward-facing parabola and the vertex is a *maximum* with the rest of the graph before it.
- DixonLv 71 month ago
Any combination is possible.