Fill in the blanks with the correct rational numbers. Write the answers using no spaces as either integers or fractions in lowest terms, e.g. "3" or "2/7", \text { Let

} s(t)=\cos \left(2 \pi f_{0} t\right) \cdot r(t)=\cos \left(2 \pi f_{1} t\right) \text {, and } u(t)=3 \sin \left(2 \pi f_{2} t\right)