1. Does a horizontal line have a gradient?
Yes, the gradient of a horizontal line is 0.
The gradient of a vertical line is undefined. i.e. It cannot be found.
2. How can you tell whether a function has a straight line graph?
In the formula for the function , the x variable and the y variable are both to the power of 1 and all terms are being added and/or subtracted. e.g 3x + 4y = 3
3. What does it mean if there is no constant term in a linear function e.g. y = 3x?
The straight line graph of the function passes through the origin (0, 0).