The denominator of the function has 10*x-1 . The range of x values passes through 1/10, at which point 10*(1/10) - 1 = 1 - 1 = 0. Therefore the function passes through exp(1/10)/0 . From below, 10*x-1 is negative, so from below it approaches negative infinity as x gets closer to 1/10, and from above 10*x-1 is positive, so it approaches positive infinity from the right of x = 1/10.
So... you have a classical non-removal discontinuity, and there is no Cauchy Principal Value available either. So the integral is undefined, which MATLAB signals to you as NaN.
