A farmer finds that if she plants 40 trees per acre, each tree will yield 55 bushels of fruit. She estimates that for each additional tree planted per acre, the yield of each tree will decrease by 3 bushels. How many trees should she plant per acre to maximize her harvest? trees Give your answer rounded to the nearest whole number.

If the range of \( y=f(x) \) is \( (-\infty, 1] \), then what is the range of \( y=|f(x)| \) ? The range of \( y=|f(x)| \) is (Type your answer in interval notation.)

\( \frac{\text { Exercices 16: }}{\text { Étudier les variations des suites ci-dessous. }} \) a) \( \left(u_{n}\right) \) définie par \( u_{0}=3 \) et, pour tout \( n \in \mathbb{N}, \operatorname{par} u_{n+1}=u_{n}+\sqrt{n} \) b) \( \left(v_{n}\right) \) définie par \( v_{0}=3 \) et, pour tout \( n \in \mathbb{N} \), par \( v_{n+1}=\frac{3}{v_{n}} \)

\( \sum _ { m - 1 } ^ { 5 } \frac { 7 } { m } = \)

3) \( f(x)=\left\{\begin{array}{ll}-2^{x}, & x<-4 \\ -|x|, & -4 \leq x \leq 0 \\ 4-x^{2}, & x>0\end{array}\right. \)

7. Graficar la siguiente función a trozos y determinar su dominio \[ f(x)=\left\{\begin{array}{ll}x^{2}+2 x & \text { si } x<-1 \\ x & \text { si }-1<x \leq 1 \\ -1 & \text { si } x>1\end{array}\right. \]