b) \( \operatorname{Lim}\left(4 x^{3}-6 x^{2}+5\right) \) cuando \( x-\cdots----3 \) c) \( \lim \left(4 x^{2}+6 x\right)\left(2 x^{3}+8 x\right) \) cuando \( x- \)

47) \( f(x)=3 x^{3}-5 x^{2}+15 x-25 \) A) \( \left\{-\frac{7}{3}, i \sqrt{5},-i \sqrt{5}\right\} \) B) \( \left\{\frac{5}{3}, i \sqrt{6},-i \sqrt{6}\right\} \) C) \( \left\{\frac{5}{3}, \frac{i \sqrt{10}}{2},-\frac{i \sqrt{10}}{2}\right\} \) D) \( \left\{\frac{5}{3}, i \sqrt{5},-i \sqrt{5}\right\} \)

49) \( f(x)=-x^{3}+3 x^{2}+3 \)

Los intervalos de crecimiento de la función \( f(x)=2 x^{3}-3 x^{2}+12 x+7 \), son: a. \( (-\infty,-2) \cup(1, x) \) b. \( (-\infty,-2) \cup(2, \infty) \) c. \( (-\infty,-1) \cup(2, \infty) \) d. \( (-1,2) \cup(2, \infty) \)

A ball is thrown from a height of 40 meters with an initial downward velocity of \( 10 \mathrm{~m} / \mathrm{s} \). The ball's height \( h \) (in meters) after \( t \) seconds is given by the following. \[ h=40-10 t-5 t^{2} \] How long after the ball is thrown does it hit the ground? Round your answer(s) to the nearest hundredth. (If there is more than one answer, use the "or" button.)

A ball is thrown from a height of 40 meters with an initial downward velocity of \( 10 \mathrm{~m} / \mathrm{s} \). The ball's height \( h \) (in meters) after \( t \) seconds given by the following. \[ h=40-10 t-5 t^{2} \] How long after the ball is thrown does it hit the ground?