Integrate 2x/sqrt(1-x^2) dx from 0 to ½.

A short-cut to accurately evaluate the given expression above is using a scientific calculator where one can include integrals and evaluate using limits. In this case, using a calculator, the answer is equal to 0.2679. One can verify this by integrating truly letting 1-x^2 as u and use its du to be substituted in the numerator

So don't take my word i'm not exactly a mathematical person but i would assume a. because while selling the soap every month you increase in sells so you would by 11 percent. the you would get the factor 0.89 which if i had to guess would be the monthly profit over 11 probably wrong tho