I'll let <em>h</em> = <em>ax</em>, so the limit is

i.e. the derivative of
.
Expand the numerator to see several terms that get eliminated:

So we have

Since <em>h</em> ≠ 0 (because it is approaching 0 but never actually reaching 0), we can cancel the factor of <em>h</em> in both numerator and denominator, then plug in <em>h</em> = 0:

Answer:
Experimental P (red) = 24 Theoretical P (Red) = 30
Experimental P (Blue) = 14 Theoretical P (Blue) = 10
Experimental P (Yellow) = 22 Theoretical P (Yellow) = 20
2cos theta = 1 -> cos theta = 1/2
Then theta = pi/3 + 2npi or -pi/3 + 2npi, where n is random interger
And the domain is restricted in [0,2pi]
So answer will be pi/3 or 5pi/3
Check the picture below.
make sure your calculator is in Degree mode, since the angles are in degrees.
It would be x= -4/7......