Let the line be y=mx+b
Substitute into the equation of the parabola and put it in quadratic form yields:
Let the discriminant be equal to 0:
The line passes through (1,3) so we sub that into the equation y=mx+b:
Solve simultaneously with the quadratic we had:
Thus, there exist no real solutions for m.
Therefore, there are no tangents that can be drawn from M which pass through (1,3).
This is also clearly seen via a diagram if you sketch the curve and the point. You will see that the point lies 'inside' the parabola, so no tangents can be drawn.