a) Calculer \( f\left(\frac{1}{2}\right) \). Dire pourquoi \( \alpha \) se trouve dans l'intervalle \( \mathrm{I}_{2} \). b) On réitère le procédé en partageant l'intervalle \( \mathrm{I}_{2} \) en deux: \( \mathrm{I}_{3}=\left[\frac{1}{2} ; \frac{3}{4}\right] \) et \( \mathrm{I}_{4}=\left[\frac{3}{4} ; 1\right] \).

Calcular \( y^{\prime}=\frac{d y}{d x} \) de la función implicita \( \frac{x^{2}}{4}+\frac{x^{2}}{9}=3 x y \) y simplificar:

\( x^{3} y+y^{2}-x^{2}=5 \) Encuentra el valor de \( \frac{d y}{d x} \) en el punto \( (2,1) \)

\( \left. \begin{array} { l } { f ( x ) = - x ^ { 4 } - 3 x ^ { 3 } } \\ { h ( x ) = - 2 ( x - 2 ) ^ { 2 } ( x + 2 ) } \end{array} \right. \)

Find the rate of change of total revenue, cost, and profit with respect to time. Assume that \( R(x) \) and \( C(x) \) are in doll \( R(x)=45 x-0.5 x^{2}, C(x)=4 x+10 \), when \( x=35 \) and \( \frac{d x}{d t}=20 \) units per day The rate of change of total revenue is \( \$ \square \) per day.

18. Fie funcția \( f: R \rightarrow R, f(x)=e^{x} \cdot\left(a x^{2}+b x+c\right) \). Determinaţi numerele reale \( a, b \) şi \( c \), ştiind că \( f(0)=0, f^{\prime}(0)=1 \) şi \( f^{\prime \prime}(0)=4 \).