Mannings formula for a rectangular channel can be written as

Q=(1/n)*sqrt(S)*((BH)^5\3 )\((B+2H)^(2\3))

where Q = flow (m3/s), n = a roughness coefficient, B = width (m), H = depth (m), and S = slope. You are applying this formula to a stream where you know that the width = 20 m and the depth = 0.3 m. Unfortunately, you know the roughness and the slope to only a 10% precision. That is, you know that the roughness is about 0.03 with a range from 0.027 to 0.033 and the slope is 0.0003 with a range from 0.00027 to 0.00033. Use a first-order error analysis to determine the sensitivity of the flow prediction to each of these two factors (i.e. n and S).

I need matlab code and the result.