Please refer to the diagram provided. I don't get the boxed step. I thought when you differentiate, you add to "1". For that question, shouldn't it be $\displaystyle \frac{9}{10}(9 - x)^{\frac{10}{9}}$ ?
Please refer to the diagram provided. I don't get the boxed step. I thought when you differentiate, you add to "1". For that question, shouldn't it be $\displaystyle \frac{9}{10}(9 - x)^{\frac{10}{9}}$ ?
it's in error, and note the antiderivative also has a negative sign ...