Exponential functions and e^x Quiz

1. Which function decreases as $x$ increases?

• A. $y=2^x$
• B. $y=e^x$
• C. $y=\left(\frac12\right)^x$
• D. $y=3^x$

2. What is the gradient of $y=e^{3x}$ at $x=0$?

• A. $1$
• B. $3$
• C. $e^3$
• D. $0$

3. Which line is the horizontal asymptote of $y=e^x-4$?

• A. $y=0$
• B. $y=4$
• C. $x=-4$
• D. $y=-4$

4. Differentiate $5e^{-2x}$.

• A. $-10e^{-2x}$
• B. $-2e^{-2x}$
• C. $10e^{-2x}$
• D. $5e^{-2x}$

5. Where does $y=e^{x+2}$ cross the $y$-axis?

• A. $1$
• B. $2$
• C. $e^2$
• D. $e$