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The range of the functions f(x) = x² + 2x + 2 is

  • (1, ∞)
  • (2, ∞)
  • (0, ∞)
  • [1, ∞)

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9 Months agoGrade
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1 Answer

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ApprovedApproved Tutor Answer9 Months ago

To find the range of the function f(x) = x² + 2x + 2, we can start by rewriting it in a more useful form. This function is a quadratic equation, and we can complete the square.

Completing the Square

We can express f(x) as follows:

f(x) = (x² + 2x + 1) + 1 = (x + 1)² + 1

Analyzing the Function

The term (x + 1)² is always non-negative (it’s zero or positive) because squares of real numbers cannot be negative. The minimum value occurs when (x + 1)² = 0, which happens at x = -1.

Finding the Minimum Value

At x = -1:

f(-1) = 0 + 1 = 1

Determining the Range

Since (x + 1)² can take any value from 0 to ∞, adding 1 shifts the entire range up by 1. Therefore, the smallest value of f(x) is 1, and it can increase indefinitely.

Final Range

The range of the function f(x) = x² + 2x + 2 is:

  • [1, ∞)