A line contains the point (-1,3) and has a slope of - 1/2. Write the equation for this line in point-slope form.

1 answer

To write the equation of a line in point-slope form, you can use the formula:

\[ y - y_1 = m(x - x_1) \]

where \((x_1, y_1)\) is a point on the line and \(m\) is the slope.

In this case, the point is \((-1, 3)\) (where \(x_1 = -1\) and \(y_1 = 3\)), and the slope \(m\) is \(-\frac{1}{2}\).

Substituting these values into the point-slope formula:

\[ y - 3 = -\frac{1}{2}(x - (-1)) \]

This simplifies to:

\[ y - 3 = -\frac{1}{2}(x + 1) \]

So the equation of the line in point-slope form is:

\[ y - 3 = -\frac{1}{2}(x + 1) \]