From elementary calculus I was met with the following problem, and I am interested if my answer is correct. The problem is to find the slopes and $y$-intercepts of the following lines:
I know that for the $y$-intercept we should set $x$ equal to zero and solve for $y$. For example, the $y$ intercept for $y=2x+3$ is $(0,3)$ and slope is $2$. For the first equation, which is a line parallel to the $y$-axis and never crosses it, I think the $y$-intercept is undefined (or maybe zero) and also the slope is the same.
But for the second equation, the $y$-intercept is $-1$ (because it crosses $y$ at $-1$ point for all values of $x$). But I think that the slope is undefined. I think this because if we compare $y=-1$ to $y=mx+b$ (where $m$ is the slope), then we can't determine a simple slope.
Please help me. Am I wrong with my thinking or not?