For the exponential function f, the value of f(1) is …

Mathematics Questions

For the exponential function f, the value of f(1) is k, where k is a constant. Which of the following equivalent forms of the function f displays k as the coefficient or the base? 1. f(x) = 50(1.6)^(x+1) 2. f(x) = 80(1.6)^(x) 3. f(x) = 128(1.6)^(x-1) 4. f(x) = 204.8(1.6)^(x-2)

Short Answer

The problem involves identifying an exponential function that reveals the constant k when x equals 1. After evaluating the provided functions, it is determined that f(x) = 128(1.6)^(x-1) satisfies this requirement, clearly displaying k as 128.

Step-by-Step Solution

Step 1: Understand the Problem

The problem requires identifying which exponential function allows the constant k to be displayed as either the coefficient or the base when the input x equals 1. We are specifically looking for a function that simplifies to k when evaluated at x = 1.

Step 2: Evaluate Each Function

We will substitute x = 1 into each of the given functions to check which function directly shows k. The functions to evaluate are:

  • f(x) = 50(1.6)^(x+1)
  • f(x) = 80(1.6)^(x)
  • f(x) = 128(1.6)^(x-1)
  • f(x) = 204.8(1.6)^(x-2)

By evaluating these, we find that only one of them yields k as a clear output.

Step 3: Identify the Correct Function

After evaluating, we find:

  • For f(x) = 128(1.6)^(x-1), substituting x=1 gives f(1) = 128(1.6)^0 = 128, directly showing k.
  • The other functions either change k through multiplication with the base or exponent, failing to display it directly.

Therefore, the function that displays k clearly is f(x) = 128(1.6)^(x-1).

Related Concepts

Exponential Function

A mathematical function of the form f(x) = a * b^(x), where ‘a’ is a coefficient, ‘b’ is the base that is raised to the power of ‘x’, and ‘x’ is the variable.

Substitution

The process of replacing a variable with a specific value in an equation or function to evaluate its output.

Evaluation

The calculation of a function’s value at a particular input, in this case, determining the output of the function when the input x equals 1.

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