what does tangent parallel to y axis mean? why is it that dy/dx = infinity? what does tangent parallel to y axis mean? why is it that dy/dx = infinity? @Mathematics

Question

anonymous · Answer

if you look at the y-axis, it is a vertical line. So when you take a tangent line, or the slope of that vertical line, you end up with another vertical line with the same slope (since its a striaght line). 

when you take a derivative, dy/dx, u are essentially finding the equation to find the slope at a particular point. Since the derivative gives you the slope you end up with that vertical line mentioned earlier. Looking more closely the change in y is pretty much infinity while the change in x is zero (indeterminate).

anonymous · Answer

eg, dy/dx = x+5/x+3 then.... if tangent is parallel to y axis, x+3 = 0 why is this so??