Problem 38
Is it possible to write \(y\) as an exponential function of \(x\) ? Explain your reasoning. (Assume \(p\) is positive.) $$ \begin{array}{|c|c|} \hline \boldsymbol{x} & \boldsymbol{y} \\ \hline 1 & p \\ 2 & 2 p \\ 3 & 4 p \\ 4 & 8 p \\ 5 & 16 p \\ \hline \end{array} $$
Problem 38
Explain why \(A=P\left(1+\frac{r}{n}\right)^{n t}\) approximates \(A=P e^{r t}\) as \(n\) approaches positive infinity.
Problem 39
You invest \(\$ 500\) in the stock of a company. The value of the stock decreases \(2 \%\) each year. Describe and correct the error in writing a model for the value of the stock after \(t\) years.
Problem 39
Solve the equation. Check for extraneous solutions. \(\log _3(x-9)+\log _3(x-3)=2\)
Problem 40
Your friend evaluates \(f(x)=e^{-x}\) when \(x=1000\) and concludes that the graph of \(y=f(x)\) has an \(x\)-intercept at \((1000,0)\). Is your friend correct? Explain your reasoning.
Problem 40
Write a rule for \(g\) that represents the indicated transformation of the graph of \(f\). \(f(x)=\log _5 x\); reflection in the \(x\)-axis, followed by a translation 9 units left
Problem 41
Write a rule for \(g\) that represents the indicated transformation of the graph of \(f\). \(f(x)=\log _{1 / 2} x\); translation 3 units left and 2 units up, followed by a reflection in the \(y\)-axis
Problem 41
Use the given information to find the amount \(A\) in the account earning compound interest after 6 years when the principal is \(\$ 3500\).\(r=2.16 \%\), compounded quarterly
Problem 41
You invest $$\$ 2500$$ in an account to save for college. Account 1 pays \(6 \%\) annual interest compounded quarterly. Account 2 pays \(4 \%\) annual interest compounded continuously. Which account should you choose to obtain the greater amount in 10 years? Justify your answer.
Problem 42
ERROR ANALYSIS Describe and correct the error in simplifying the expression \(\log _4 64^x\). \(\begin{aligned} \log _4 64^x &=\log _4\left(16 \cdot 4^x\right) \\ &=\log _4\left(4^2 \cdot 4^x\right) \\ &=\log _4 4^{2+x} \\ &=2+x \end{aligned}\)