IDNLearn.com: Your go-to resource for finding precise and accurate answers. Get the information you need from our experts, who provide reliable and detailed answers to all your questions.

Which statements are true of the function [tex]f(x)=3(2.5)^x[/tex]? Check all that apply.

A. The function is exponential.
B. The initial value of the function is 2.5.
C. The function increases by a factor of 2.5 for each unit increase in [tex]x[/tex].
D. The domain of the function is all real numbers.
E. The range of the function is all real numbers greater than 3.


Sagot :

To analyze the function [tex]\( f(x) = 3(2.5)^x \)[/tex], let's go through each statement step by step:

1. The function is exponential.
- An exponential function is of the form [tex]\( f(x) = a \cdot b^x \)[/tex], where [tex]\( a \)[/tex] is a constant and [tex]\( b \)[/tex] is the base of the exponent that is positive and not equal to 1.
- Here, [tex]\( f(x) = 3(2.5)^x \)[/tex] fits this form with [tex]\( a = 3 \)[/tex] and [tex]\( b = 2.5 \)[/tex]. Therefore, this is indeed an exponential function.
- True

2. The initial value of the function is 2.5.
- The initial value of a function is the value when [tex]\( x = 0 \)[/tex].
- Substituting [tex]\( x = 0 \)[/tex] into the function, we get [tex]\( f(0) = 3(2.5)^0 = 3 \cdot 1 = 3 \)[/tex].
- Therefore, the initial value is 3, not 2.5.
- False

3. The function increases by a factor of 2.5 for each unit increase in [tex]\( x \)[/tex].
- This means that for every 1-unit increase in [tex]\( x \)[/tex], the value of the function is multiplied by 2.5.
- This is a characteristic of the exponential function [tex]\( f(x) = 3(2.5)^x \)[/tex]. Therefore, it is true.
- True

4. The domain of the function is all real numbers.
- The domain of an exponential function is all real numbers because you can substitute any real number into the exponent and still have a valid output value.
- Therefore, the domain of [tex]\( f(x) = 3(2.5)^x \)[/tex] is all real numbers.
- True

5. The range of the function is all real numbers greater than 3.
- The range of an exponential function [tex]\( a \cdot b^x \)[/tex] where [tex]\( a > 0 \)[/tex] and [tex]\( b > 1 \)[/tex] is all positive real numbers greater than 0.
- For [tex]\( f(x) = 3(2.5)^x \)[/tex], as [tex]\( x \)[/tex] approaches negative infinity, [tex]\( f(x) \)[/tex] approaches 0 but never reaches 0. It is always positive.
- The range is all real numbers greater than 0, not greater than 3.
- False

Putting it all together, here are the true statements about the function [tex]\( f(x) = 3(2.5)^x \)[/tex]:

1. The function is exponential.
2. The function increases by a factor of 2.5 for each unit increase in [tex]\( x \)[/tex].
3. The domain of the function is all real numbers.

And here are the false statements:

1. The initial value of the function is 2.5.
2. The range of the function is all real numbers greater than 3.

Hence, the result is: `(True, False, True, True, False)`.