Ana was interested in the relationship between funding sources for nutritional researches and the conclusions of those researches. She gathered information on all researches concerning soft drinks that were published between 1 January, 1999 and 31 December, 2003, and compared the source of their funding with the results of the research. What type of a statistical study did Ana use? Choose 1 answer: (A) Sample study (B) Experiment (C) Observational study

\( =\left\{\begin{array}{ll}\frac{2 \exp (1-\cos (\sqrt{x}))+\sin (x)-2}{x} & \text { se } x>0 \\ b x e^{a x}+a & \text { se } x \leq 0\end{array}\right. \)

\( 3^{\circ} \) Siendo " \( a \) " la pendiente de la recta \( y \) " \( b \) " la ordenada al origen, escribí las funciones \( y \) grafica sin tabla. \( \begin{array}{rrrr}\text { 1) } a=-\frac{1}{3} & \text { 2) } a=4 & \text { 3) } a=\frac{5}{2} & \text { 4) } a=\frac{3}{2} \\ b=-2 & b=0 & b=-1 & b=3\end{array} \)

Tho following inequality is given: \( 3(x+7)<\frac{x}{2}+1 \) 2.2.1 Solve for \( x \) in the inequality.

How much time passes from 1 January until 23 January? How much time passes from 06:00 on 5 January until 14:00 on 7 January? f) How much time passes from 07:13 on 12 January until 23:45 on 29 January?

the perimeter of a rectangle is equal to \( 18+\sqrt{180} \mathrm{~cm} \). if the length and width of this rectangle are proportional to the golden ratio, what is the length of the rectangle?