A line passes through (2,1), (0,-2), (-2,-3), what is the y intercept?

May 27, 2015

It will be $y = - 2$
You can see this from your second set of coordinates where for $x = 0$ you get $y = - 2$:
Graphically:

May 27, 2015

Obviously, given the second data point $\left(0 , - 2\right)$
$\left(- 2\right)$ is a y-intercept
but the given data points (2,1), (0,-2), (-2,-3) are not points on a straight line,

The underlying equation could be a parabola (with a horizon axis of symmetry) or some more complex relationship.
Other y-intercepts are possible.