# What is Multiplication of Rational Expressions?

In fact, if you have two rational expressions $\frac{a}{b}$ and $\frac{c}{d}$ the product $\frac{a}{b} \setminus \cdot \frac{c}{d}$ is simply a fraction whose numerator is the product of the numerators, and whose denominator is the product of the denominators, i.e. $\frac{a c}{b d}$.
$\setminus \frac{{x}^{2}}{{e}^{x}} \setminus \cdot \setminus \frac{\setminus \cos \left(x\right)}{{x}^{2} + 1} = \setminus \frac{{x}^{2} \setminus \cos \left(x\right)}{{e}^{x} \left({x}^{2} + 1\right)}$