Beginning with Equation 9.46, [R_{X F}left(alpha_{1} ight)=int_{-infty}^{infty} gleft(tau_{1} ight) R_{F F}left(alpha_{1}-tau_{1} ight) d tau_{1}] derive Equation 9.49,

Beginning with Equation 9.46,

\[R_{X F}\left(\alpha_{1}\right)=\int_{-\infty}^{\infty} g\left(\tau_{1}\right) R_{F F}\left(\alpha_{1}-\tau_{1}\right) d \tau_{1}\]

derive Equation 9.49,

\[R_{X X}(\tau)=\int_{-\infty}^{\infty} \int_{-\infty}^{\infty} g(\alpha) g(\beta) R_{F F}(\tau+\beta-\alpha) d \alpha d \beta\]