a) Un artesano quiere fabricar un dado hueco de plata de 18 mm de lado - ¿Qué área debe tener cada cara? \( \begin{array}{lll}\text { a) } 36 \mathrm{~mm}^{2} & \text { b) } 864 \mathrm{~mm}^{2} & \text { c) } 324 \mathrm{~mm}^{2}\end{array} \)

Let \( h(x) = 4-\frac{1}{x} \) and \( k(x) = 5x + 3 \). Calculate \( (h \circ k)(x) \).

Graph each function on the indicated domain, and use the capabilities of your calculator to find the location and value of the absolute extrema. 29. \( f(x)=\frac{-5 x^{4}+2 x^{3}+3 x^{2}+9}{x^{4}-x^{3}+x^{2}+7} ; \quad[-1,1] \) 30. \( f(x)=\frac{x^{3}+2 x+5}{x^{4}+3 x^{3}+10} ; \quad[-3,0] \)

8. A square loop of side \( a=50 \mathrm{~cm} \) is suspended from the left arm of a scale, which is kept at equilibrium by adding weights to the right side. The lower half of the loop is in a uniform magnetic field of magnitude 0.4 T , orthogonal to the surface of the loop, but the upper half is outside the magnetic field. (a) It is observed that when a current \( I \) flows in the loop, one needs to add 25 g to the right arm to bring the scale back to equilibrium. Find the current flowing in the loop. (b) If the direction of current were now to be reversed, what would need to be done to bring the scale back to equilibrium? \( \bullet \)

Matthew's mother Selma used cocaine when she was pregnant, and Matthew was born drug-addicted. It is likely that a. he will be very attentive to the environment b. his motor development will be especially rapid during the first year c. his cries will be abnormally shrill d. he will overcome the harmful effects of drug exposure by age 3

Through secondary circular reactions, babies a. suck, grasp, and look in much the same way, no matter what experiences they encounter b. try to repeat interesting events that are caused by their own actions c. repeat behaviors with variation, deliberately exploring the environment d. repeat chance behaviors that are largely motivated by basic needs Clear my choice