Identify which of the following functions is one-to-one.(1 point)

Responses

g(x)=2x−4
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2
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4
g left parenthesis x right parenthesis equals 2 x minus 4

g(x)=2x2
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2
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2
g left parenthesis x right parenthesis equals 2 x squared

g(x)=−6x4+2x−1
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6
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4
+
2
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1
g left parenthesis x right parenthesis equals negative 6 x superscript 4 baseline plus 2 x minus 1

g(x)=x2−4x+1

1 answer

To determine which of the given functions is one-to-one, we can analyze them individually. A function is one-to-one if it assigns a unique output for every unique input, meaning \(g(a) = g(b)\) implies \(a = b\).

  1. g(x) = 2x - 4

    • This is a linear function with a non-zero slope (2). Linear functions with a slope not equal to zero are one-to-one.
  2. g(x) = 2x²

    • This is a quadratic function. Quadratic functions are generally not one-to-one because they can produce the same output for different inputs (for example, \(g(1) = g(-1) = 2\)).
  3. g(x) = -6x⁴ + 2x - 1

    • This is a polynomial function of degree 4 (even degree) and has a higher degree term that is negative. Polynomial functions of even degree are typically not one-to-one since they can have turning points and exhibit symmetry.
  4. g(x) = x² - 4x + 1

    • This is a quadratic function that can also be expressed as \(g(x) = (x - 2)² - 3\). As with the previous quadratic function, this one is not one-to-one because it can also yield the same output for multiple inputs.

From this analysis:

  • g(x) = 2x - 4 is the only one-to-one function among the given options.