\magnification=\magstep1 \input amstex \documentstyle{amsppt} \document \NoBlackBoxes \nologo \flushpar{\bf{Math 1251 Exam 1 January 27, 1995}} \qquad Your Name {$\underline{\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ }$} \newline {\bf{Professor Stanton}} \vskip 3pt \flushpar{\it{Directions}}: {\eightpoint{You may use your notes, books, and calculators. This exam has 8 problems with the point values indicated. Circle your answer to the multiple choice questions . If you use a table (or calculator) to find your answer, write down the word ``table'' (or ``calculator'') next to your answer. If your answer is correct, you will receive full credit for that problem, otherwise you will be awarded 0 points. This means if you copy a minus sign incorrectly you will be given 0 points. An answer alone with no justification is worth 0 points.}} \vskip 3pt \flushpar (10) 1. If $f(x)=(5-2/x)^{100}$, then $f'(x)=$\newline (a) $100(5-2/x)^{99}$\flushpar (b) $200(5-2/x)^{99}/x$\flushpar (c) $400(5-2/x)^{99}/x^2$\flushpar (d) $1000(5-2/x)^{99}$\flushpar (e) none of the above. \vskip5pt\flushpar (10) 2. If $y=tan(x)/x^2$, then $\frac{dy}{dx}$=\newline (a) $sec(x)/x^2$\flushpar (b) $sec^2(x)/x^2+sin(x)/(2x)$\flushpar (c) $tan(x)/(2x)$\flushpar (d) $-2 tan(x)/x^3 +sec^2(x)/x^2$\flushpar (e) none of the above. \vskip 5pt \flushpar (10) 3. If $f(x)= \sqrt{1+cos(x^2)}$, then $f'(x)=$\newline (a) $(1+cos(x^2))^{-1/2}/2$\flushpar (b) $\sqrt{|sin(x^2)|}$\flushpar (c) $\frac{-xsin(x^2)}{\sqrt{1+cos(x^2)}}$\flushpar (d) $-sin(x)$\flushpar (e) none of the above. \vskip 5pt \flushpar (10) 4. $$ \lim_{x\to 0}\frac{xtan(x)(x^6+12)(cos(sin(x))} {sin(2x)sin(3x)(x^{12}+14x^5+3x+1)}= $$ \newline (a) $0$\flushpar (b) $12$\flushpar (c) $3$\flushpar (d) $2$\flushpar (e) does not exist. \vfill \pagebreak \flushpar (12) 5. Find the equation of the tangent line to the graph of $y=x\sqrt{x}+x$ at $(4,12)$.\flushpar \vskip100pt\flushpar (12) 6. The position function of a particle is given by $s=4t^3-12t$. \flushpar (a) Find the average velocity during $1\le t\le3$.\flushpar (b) Find the instantaneous velocity at $t=3$.\vskip 120 pt\flushpar (8) 7. Give an example of a function $f(x)$, which is continuous at all real numbers $x$, but is not differentiable at integer values of $x$.\vskip100pt\flushpar (8) 8. True or False. (You must give at least one reason for your answer in a complete sentence. An answer alone is worth zero.)\newline If $f(x)$ is a continuous function for all real $x$ which satisfies $0\le f(x)\le1$, then $\lim_{x\to\infty} f(x)$ must exist. \vfill \enddocument \end \magnification=\magstep1 \input amstex \documentstyle{amsppt} \document \NoBlackBoxes \nologo \flushpar{\bf{Math 1251 Exam 2 February 23, 1995}} \qquad Your Name {$\underline{\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ }$} {\bf{Professor Stanton}} \vskip 3pt \flushpar{\it{Directions}}: {\eightpoint{You may use your notes, books, and calculators. This exam has 8 problems with the point values indicated. Circle your answer to the multiple choice questions. If you use a table (or calculator) to find your answer, write down the word ``table'' (or ``calculator'') next to your answer. If your answer is correct, you will receive full credit for that problem, otherwise you will be awarded 0 points. This means if you copy a minus sign incorrectly you will be given 0 points. An answer alone with no justification is worth 0 points.}} \vskip 3pt \flushpar (10) 1. If $f(x)=e^{-x^2 ln(x)}$, then $f'(x)=$\newline (a) $e^{-x^2ln(x)}(-2xln(x))$\flushpar (b) $e^{-2xln(x)}$\flushpar (c) $e^{-x^2ln(x)}(-x)$\flushpar (d) $x^{-x^2}$\flushpar (e) none of the above. \vskip5pt\flushpar (10) 2. If $x\thinspace tan^{-1}(y)=y^2$, then $\frac{dy}{dx}$=\newline (a) $x/(1+y^2)+tan^{-1}(y)$\flushpar (b) $(2y-tan^{-1}(y))(1+y^2)/x$\flushpar (c) $tan^{-1}(y)/(2y-\frac{x}{1+y^2})$\flushpar (d) $x/(2y(1+y^2))$\flushpar (e) none of the above. \vskip 5pt \flushpar (10) 3. If $f(x)=x\thinspace e^{2x}$ then $f''(1)=$\newline (a) $8e^2$\flushpar (b) $e^2$\flushpar (c) $0$\flushpar (d) $3e^2$\flushpar (e) none of the above. \vskip 5pt \flushpar (10) 4. $$ \lim_{x\to \infty}\frac{tan^{-1}(x)(2e^{2x}+ln(x))} {\sqrt{x}+e^{2x}}= $$ \newline (a) $0$\flushpar (b) $2$\flushpar (c) $1$\flushpar (d) $\pi$\flushpar (e) does not exist. \vskip 5pt \flushpar (10) 5. The best linear approximation to $y=\sqrt{x}$ at $x=4$ is\newline (a) $y=x$\flushpar (b) $y-2=x-4$\flushpar (c) $y-4=x-2$\flushpar (d) $y-2=(x-4)/4$\flushpar (e) none of the above. \vskip5pt\flushpar \vfill \pagebreak \flushpar (10) 6. A population of bacteria is exponentially decaying. In one hour the population decreases from 2000 to 1500. What is the population after 2.5 additional hours?\flushpar \vskip150pt\flushpar (10) 7. A gas is trapped in a balloon at a constant temperature. It is known that the volume, $V$, and the pressure $P$ of such a gas are related by $PV=c$, where $c$ is a fixed constant. The volume of the balloon is increasing at the constant rate of 4 ml/sec. Find the rate of change of the pressure with respect to time when the pressure is 2 and the volume is 5. \vskip 160 pt\flushpar (10) 8. Give an explicit function $f(x)$ such that $$\lim_{x\to\infty}\frac{f(x)}{x}=0 \quad{\text{and}}\quad \lim_{x\to\infty}\frac{f(x)}{ln(x)}=\infty. $$ \vfill \enddocument \end