Question

Use the graph to write a linear function that relates y to x .

Answer 1

2y = x + 2

Explanation:

Looking at the graph, we can see from one point to the next (from right to left), the x-value rises by 2 and the y-value by 1;

From this we can work out the gradient between two points using the formula, i.e. the change/difference in y divided by the change/difference in x:

`m = (dy)/(dx) = (1)/(2)`

Joining the points gives a straight line, which means a constant gradient of ¹/₂

Use the line equation formula to get the function:

y - y₁ = m(x - x₁)

m = ¹/₂

x₁ = 0

y₁ = 1

y - 1 = ¹/₂.(x - 0)

y - 1 = ¹/₂.x

2y - 2 = x

2y = x + 2