## Calculus 10th Edition

$u=\frac{5}{2}x.$ $y=\sin{u}.$
Working from the inside out: Take $x$; multiply it by $\dfrac{5}{2}\leftarrow$ "inner function." Take $\frac{5}{2}x$; take the sine of it $\leftarrow$ "outer fucntion." $u=\frac{5}{2}x.$ $y=\sin{u}.$