title: How to find the normal vector at a point on a curve in MatLab
body: <p>I have a curve and I want to find the normal vector at a given point on this curve, later I have to find the dot product of this normal vector with another vector.</p>
  
  <p>I tried the gradient function of MatLab, but I guess it doesnt work when we need to find the gradient at a specific point still I am not sure if I am wrong.</p>
  
  <p>Please guide me how can I achieve this in MatLab.</p>
  
  <p>Thanks in advance.</p>