## Calculus (3rd Edition)

Compare the given equations with the linear equation $a_{n}(x) y^{(n)}+a_{n-1}(x) y^{(n-1)}+\cdots+a_{1}(x) y^{\prime}+a_{0}(x) y=b(x)$ We see that: ( a) It is linear. ( b) It is not linear. Notice the $y^2$ term. ( c) It is not linear. Notice the $(y')^3$ term. ( d) It is not linear. Notice the $\sin y$ term ( e) It is linear. ( f) It is not linear. Notice the $yy'$ term.