4. ( 5 pts) Find the limit \( \lim _{(x, y) \rightarrow(0,0)} \frac{x^{4}+y^{4}}{y^{4}-x^{3}} \) (Hint: Find the limit along \( x \)-axis, \( y \)-axis, or \( y=x \) line.)

\( \int \frac { 3 / \sqrt { a ^ { 3 } y ^ { 4 } } x d x } { 4 / 3 a ^ { 2 } b ^ { 3 } x ^ { 2 } + 6 } \)

1) \( \int_{8}^{\frac{\text { III }}{\frac{\pi}{2}}} x \cdot c \)

\( \lim _ { x \rightarrow \infty } ( \frac { 3 x + 1 } { 3 x - 5 } ) ^ { \frac { 3 x ^ { 5 } + 4 x - 3 } { ( 2 x - 1 ) ^ { 2 } ( x + 2 ) ^ { 2 } } } \)

Integrate as indicated. Assume \( \mathrm{g}(\mathrm{x})>0 \) whenever \( \ln g(\mathrm{x}) \) is involved. \( \int \frac{8 \mathrm{x}}{4 \mathrm{x}^{2}+1} \mathrm{dx} \) \( \int \frac{8 \mathrm{x}}{4 \mathrm{x}^{2}+1} \mathrm{dx}= \)

10.- Calcula la derivada de la función * \( y=12 x^{4}+5 x^{3}-3 x^{2}+5 \) \( \begin{array}{ll}\text { A) } \frac{d y}{d x} 48 x^{3}+15 x^{2}-6 x & \text { B) } \frac{d y}{d x} 48 x^{4}+15 x^{2}-6 x \\ \text { C) } \frac{d y}{d x} 48 x^{3}+15 x^{2}+6 x & \text { D) } \frac{d y}{d x} 48 x^{2}+15 x^{2}-6 x\end{array} \)