Question

How do you write the equation in point slope form given (1,5) and (-3,3)?

Answer 1

The slope is `1/2` and the y-intercept is `4 1/2` (see calculations below), so the equation of the line in point-slope form is `y=1/2 x + 4 1/2`

Explanation:

You need to find the gradient (slope) and the y-intercept.

To find the gradient:

`m=(y_2-y_1)/(x_2-x_1)=(3-5)/((-3)-1)=1/2`.

Use `y=mx+c=1/2x+c` and substitute in either of the points to find the value of `c`:

`5=1/2(1)+c` gives `c=4 1/2`

Over all, then, `y=1/2 x + 4 1/2`