Calculating Area Under Curve with Trapezium Rule

[henryc09]

Homework Statement

A modified form of the trapezium rule for calculating the area under a curve makes use of strips
of varying width: by using narrower strips where the gradient varies more rapidly, better
accuracy can be achieved. Create a function to perform the integral

\int1/x dx between 1 and 101

using the trapezium rule with strips that increase geometrically in width, such that,

\DeltaX_n=r^n-1\DeltaX₁ where \DeltaX_n is the width of the nth strip and r is a constant (which is an
input to the function).
Choose the value of Δx1 to give a total of 100 strips for any value of r (hint: you will need the
formula for the sum of a geometric progression to calculate Δx1).

Homework Equations

The Attempt at a Solution

Not sure where to start really, I mean a simple application of the trapezium rule to it would be simple enough. Define a vector x=[1:1:101] and then y=1./x and integral=trapz(x,y) or something along those lines (I don't have access to MATLAB from home so I couldn't be sure). Any point in the right direction would be much appreciated.

 

[mangofun12]

Did you ever find an answer to this question?