Easy -2.0 This is a 1-mark multiple choice question requiring only basic recall that exponential functions with positive bases are always increasing, and negating them makes them decreasing. Students need only recognize that -e^(anything with positive coefficient of x) is decreasing, making this significantly easier than average A-level questions.
Which one of these functions is decreasing for all real values of \(x\)?
Circle your answer.
\(f(x) = e^x\) \quad \(f(x) = -e^{1-x}\) \quad \(f(x) = -e^{x-1}\) \quad \(f(x) = -e^{-x}\)
[1 mark]
Which one of these functions is decreasing for all real values of $x$?
Circle your answer.
$f(x) = e^x$ \quad $f(x) = -e^{1-x}$ \quad $f(x) = -e^{x-1}$ \quad $f(x) = -e^{-x}$
[1 mark]
\hfill \mbox{\textit{AQA Paper 2 2020 Q1 [1]}}