The outer shape of a football can be described via the following equation

Using Matlab, plot the outer shape of a football in  red or orange using a line width of 2 for R = 12 and r = 4. When defining the x-vector, use three different interval steps: (a) dx=4, (b) dx=2 and (c) dx=0.01. Plot each football in a separate plot.

When plotting your football,

• Set the limit of the x and y-axis to [min= -15 max= +15]. 
• Label both axes, 
• Set a title (for instance 'Problem 2 - Football with dx=2'), 
• Use a grid 
• Use the 'axis equal' to make sure that your figure is not stretched.

Note:  For x ∈ [0,(R, -r)] the equation will give you  one quarter  of the contour of a football.