\begin{tabular}{l}\begin{tabular}{l} 5. ¿Cuál es el radio de un \\ gorro en forma de cono \\ cuyo volumen es \( 432 \mathrm{~m} \mathrm{~cm}^{3} \) \\ y su altura 12 cm ? \\ \( \begin{array}{l}\text { 7. ¿Cuál es la base menor de } \\ \text { un terreno en forma de } \\ \text { trapecio cuya área es } \\ 81 \mathrm{~m}^{2} \text {, su altura es } \mathrm{sm} \text { y su } \\ \text { base mayor } 10 \mathrm{~m} \text { ? }\end{array} \) \\ \hline\end{tabular} \\ \hline\end{tabular}

7. En cada ítem, estudiar la posición relativa entre las dos rectas dadas y graficar ambas en un mismo sistema de coordenadas cartesianas. a) \( \left\{\begin{array}{l}x=1-5 \lambda \\ y=2+3 \lambda \\ z=-5+\lambda\end{array}\left\{\begin{array}{l}x=1 \\ y=1 \\ z=\mu\end{array}(\lambda, \mu \in \mathbb{R})\right.\right. \) b) \( \left\{\begin{array}{l}x=3+2 \alpha \\ y=1-\alpha \\ z=5\end{array}\left\{\begin{array}{l}x=-1-6 \beta \\ y=3+3 \beta \\ z=5\end{array} \quad(\alpha, \beta \in \mathbb{R})\right.\right. \)

10.A circle, centre \( C \), has a diameter \( P Q \) where \( P \) is the point \( (-1,-1) \) and \( Q \) is the point \( (5,7) \). (a) Show that the equation of the circle is \( x^{2}+y^{2}-4 x-6 y-12=0 \).

En cada ítem, estudiar la posición relativa entre las dos rectas dadas y graficar ambas en un mismo sistema de coordenadas cartesianas. a) \( \left\{\begin{array}{l}x=1-5 \lambda \\ y=2+3 \lambda \\ z=-5+\lambda\end{array}\left\{\begin{array}{l}x=1 \\ y=1 \\ z=\mu\end{array} \quad(\lambda, \mu \in \mathbb{R})\right.\right. \)

a. Determine the radius and the co-ordinates of the centre of the circle given by the equation \[ x^{2}+y^{2}+8 x-2 y+8=0 \] [5 marks] b. Find the point of intersection of the circle \( x^{2}+y^{2}-2 x-8 y-6=0 \) and the line \( x+y=2 \) c. Find the equation of the tangent and the length of the tangent to the circle \( 4 x^{2}+4 y^{2}-2 x+5 y-8=0 \) from the point \( (-4,4) \). 5 marks \( ] \) d. Given the circle \( (x-2)^{2}+(y+3)^{2}=16 \), sketch the graph of the circle. [5 marks]

Find the slope of the line passing through the given points. (If an answer is undefined, enter UNDEFINED.) \[ (7,-4) \text { and }(7,-3) \]