Avec un(e) camarade, indiquez quelle sorte de cadeau on re$\c[c]$oit d’habitude $\`a$ l’occasion des f$\^e$tes sur la liste. Pour quelles occasions est-ce que vous et votre camarade ont indiqué le m$\^e$me cadeau? Pour quelles occasions avez-vous des idées compl$\`e$tement diff$\`e$rentes?

1. un(e) adolescent / Noel
2. les enfants / P$\^a$ques
3. votre m$\`e$re ou p$\`e$re / la f$\^e$te des M$\`e$res ou des P$\`e$res
4. votre copain ou copine / la Saint-Valentin
5. vous / votre anniversaire
6. vous et vos fr$\`e$res et sceurs / la remise des dipl$\^o$mes ( "graduation")

An 80.0-kg skydiver jumps out of a balloon at an altitude of 1 000 m and opens his parachute at an altitude of 200 m. (a) Assuming the total retarding force on the skydiver is constant at 50.0 N with the parachute closed and constant at 3 600 N with the parachute open, find the speed of the skydiver when he lands on the ground. (b) Do you think the skydiver will be injured? Explain. (c) At what height should the parachute be opened so that the final speed of the skydiver when he hits the ground is 5.00 m/s? (d) How realistic is the assumption that the total retarding force is constant? Explain.

Using complete sentences, first tell if these items are in your classroom. Then tell how many of each there are.

Des ordinateurs?

If the triple product $(\mathbf{v} \times \mathbf{j}) \cdot \mathbf{k}$ is zero, what can you say about the vector $\mathbf{v}$ ?

Write the partial fraction decomposition of each rational expression. $\frac{x-4}{x^{2}(x-1)}$

The value of Henry's constant for $\mathrm{CO}_{2}$ gas dissolved in water at 290 K is 12.8 MPa. Consider water exposed to atmospheric air at 100 kPa that contains 3 percent $\mathrm{CO}_{2}$ by volume. Under phase equilibrium conditions, the mole fraction of $\mathrm{CO}_{2}$ gas dissolved in water at 290 K is (a) $2.3 \times 10^{-4}$ (b) $3.0 \times 10^{-4}$ (c) $0.80 \times 10^{-4}$ (d) $2.2 \times 10^{-4}$ (e) $5.6 \times 10^{-4}$

In this exercise, you will need to use a graphing utility to confirm your result.

$$f(x)=\sin x-\sqrt{3} \cos x$$

Solve. $\\$$\left(5 x^2+6 x\right)\left(12 x^2-5 x-2\right)=0$

determine whether each ordered triple is a solution of the system of equations. { -4x - y - 8z = -6, y + z = 0, 4x - 7y = 6. (-2, -2, 2)

Using complete sentences, first tell if these items are in your classroom. Then tell how many of each there are.

Des pasters?

When one mole of carbon disulfide gas reacts with hydrogen gas, methane and hydrogen sulfide gases are formed. When equilibrium is reached at $900^{\circ} \mathrm{C}$, analysis shows that $P_{\mathrm{CH}_4}=0.0833 \mathrm{~atm}, P_{\mathrm{H}_2 \mathrm{~S}}=0.163 \mathrm{~atm}, P_{\mathrm{CS}_2}=$ $1.27 \mathrm{~atm}$, and $P_{\mathrm{H}_2}=0.873 \mathrm{~atm}$. (a) Write a balanced equation (smallest whole-number coefficients) for the reaction. (b) Find $K$ at $900^{\circ} \mathrm{C}$.

Propane gas, $C_3H_8$, undergoes combustion with oxygen gas to produce carbon dioxide and water gases. Propane has a density of $2.02$ g/L at room temperature. How many grams of $H_2O$ can be produced from the reac- tion of $100$. g of $C_3H_8$?

Solve each problem. See the example in this section.

A frog leaps from a stump $3 \mathrm{~ft}$ high and lands $4 \mathrm{~ft}$ from the base of the stump. We can consider the initial position of the frog to be at $(0,3)$ and its landing position to be at $(4,0)$. See the figure. It is determined that the height of the frog as a function of its horizontal distance $x$ from the base of the stump is given by

$$h(x)=-.5 x^2+1.25 x+3,$$

where $x$ and $h(x)$ are both in feet.

At what two horizontal distances from the base of the stump was the frog $3.25 \mathrm{~ft}$ above the ground?

Graph the solution set.

$$\left(x^2+1\right)\left(x^2-3 x+2\right)>0$$