340 If the straight line \( L_{1} \) passes through the two points \( (3,1) \) and \( (2, k) \) and the straight line \( L_{2} \) makes with the positive direction of the \( x \)-axis a positive angle whose measure is \( 45^{\circ} \), then find \( k \) if the two straight lines \( L_{1} \) and \( L_{2} \) are : \( \begin{array}{ll}\text { [1] parallel } & \text { [2] perpendicular }\end{array} \)

Si \( A=\{2,3\} \) y \( B=\{1,4,5\} \), encontrar tres celaciones dejinidad de \( A \) en \( B \).

5. \( \left\{\begin{array}{l}15 x+11 y=32 \\ 7 y-9 x=8\end{array}\right. \)

2.4 A body of mass m is kept on the inclined plane which makes an angle \( \theta \) with horizontal then normal force on the body is: \( \begin{array}{llll}\text { a. } m g \sin \theta & \text { b. } m g \cos \theta & \text { c. } m g & \text { d. } m g \tan \theta\end{array} \)

(4) Encuentre el área del paralelo gramo con vertice consecutivos \( P(2,4,-1), Q(3,2,5), R(-2,2,7) \)

5. The cubic equation \( 2 z^{3}+p z^{2}+q z+r=0 \) has roots \( \frac{\alpha}{k}, \alpha, k \alpha \). (i) Express \( p, q \) and \( r \) in terms of \( k \) and \( \alpha \).