$$ \int k \, dx = kx + C $$ $$ \int x^a \, dx = \frac{1}{a+1} x^{a+1} + C \quad(a \neq -1) $$ $$ \int \frac{1}{x} \, dx = \log |x| + C $$ $$ \int e^x \, dx = e^x + C $$