Question

Graph the function and analyze it for domain, range, continuity, increasing or decreaseing behavior, symmetry, boundedness, extrema, asymptotes, and end behavior.
f(x) = 3 * 0.2^x

Answer 1

Answer:

$f(x) = 3 \cdot 0.2^x$

Step-by-step explanation:

$f(x) = 3 \cdot 0.2^x$

Domain of f: "What values of x can we plug into this equation?" This makes sense for all real numbers so the domain is $\mathbb{R}$

Range of f: "What values of f(x) can we get out of the function?" From the graph we see we can get any real number greater than 0 out of the function by choosing a suitable x-value in the domain. The range is therefore $(0, \infty)$.

Continuity: Since the graph is one, unbroken curve (i.e. a curve that can be drawn in one movement without taking your pen off the paper). We see that "roughly speaking" the function is continuous.

Increasing or decreasing behaviour: For all x in the domain, as x increases, f(x) decreases. This means the function exhibits decreasing behaviour.

Symmetry: It is clear to see the graph of f(x) has no symmetry.

Boundedness: Looking at the graph we see it is unbounded above as when we choose negative values, the graph of f(x) explodes upwards exponentially. Choose a value of x, plug it in, next choose (x-1), plug this in and we observe $f(x-1) > f(x)$ for all x in the domain.

The function is however bounded below by 0: no value of x in the domain exists which satisfies $f(x) < 0$.

Extrema: As far as I can tell, there are no turning points on the curve. (Is this what you mean by extrema?)

Asymptotes: Contrary to the curve's appearance, there are no vertical asymtotes for this curve. The negative-x portion of the curve is just growing so quickly it appears to look like an asymptote. There is a value of f(x) for all x<0. There is however a horizontal asymtote: $y=0$.

End behaviour: As $x \rightarrow \infty, f(x) \rightarrow 0$. As $x \rightarrow -\infty, f(x) \rightarrow +\infty$