Question

Where is the y-intercept of `y=2x+0.5` on a graph?

Answer 1

The y-intercept is obtained by putting `x=0` in your equation.

In your case you get `y=2*0+0.5`;
`y=0.5`

The curve represented by your equation (a straight line) intercepts the y-axis at the point of coordinates `(0;0.5)`;
graph{2x+0.5 [-2.5, 2.5, -1.25, 1.25]}