Question

Geraldine is asked to explain the limits on the range of an exponential equation using the function f(x) = 2x. She makes these two statements: 1. As x increases infinitely, the y-values are continually doubled for each single increase in x. 2. As x decreases infinitely, the y-values are continually halved for each single decrease in x. She concludes that there are no limits within the set of real numbers on the range of this exponential function. Which best explains the accuracy of Geraldine's statements and her conclusion?

Answer 1

"as x increases infinitely, the y-values are continually doubled for each single increase in x".

Explanation:

Given the exponential equation f(x) = 2x of which Geraldine is asked to explain the limits on the range, the expression that best explains the accuracy of Geraldine's statements and her conclusion is that "as x increases infinitely, the y-values are continually doubled for each single increase in x".

for example let y = f(x) so thet y = 2x

for every va;ues of x, y will be doubled as shown;

If x = 1

y = 2(1) = 2

If x = 2

y = 2(2) = 4

If x = 3

y = 2(3) = 6

I can be seen that the value of y doubles for all values of x hence making her first statement accurate.

The second statement 'As x decreases infinitely, the y-values are continually halved for each single decrease in x'. is not totally right because the y values may not be halved for some values of x as x increases.

Her conclusion is not also right because there are limits within the set of real numbers on the range of this exponential function. for every value of x, y will always tend to a real value.