Question

Difficulty: EasyFunctions and Custom Symbol Operations

For all real numbers xx, the function gg is defined by g(x)=5−2x2g(x) = 5 - 2x^2. What is the value of g(g(2))g(g(2))?

  1. A
    23
  2. -13Answer
  3. C
    11
  4. D
    3
  5. E
    9

Answer

-13
Evaluating the inner expression g(2)g(2) gives 5−2(2)2=5−8=−35 - 2(2)^2 = 5 - 8 = -3. Substituting −3-3 back into the function g(x)g(x) gives g(−3)=5−2(−3)2=5−2(9)=−13g(-3) = 5 - 2(-3)^2 = 5 - 2(9) = -13. Thus, the correct value is −13-13.

Step-by-Step Solution

1
Evaluate the inner function g(2)g(2)
g(2)=5−2(2)2=5−2(4)=5−8=−3g(2) = 5 - 2(2)^2 = 5 - 2(4) = 5 - 8 = -3
Substitute x=2x = 2 into the definition of g(x)g(x) and follow standard order of operations (exponents before multiplication).
2
Substitute the result into the outer function to evaluate g(−3)g(-3)
g(−3)=5−2(−3)2=5−2(9)=5−18=−13g(-3) = 5 - 2(-3)^2 = 5 - 2(9) = 5 - 18 = -13
Squaring a negative number yields a positive result, so (−3)2=9(-3)^2 = 9, which is then multiplied by 22.

Key Concept

Nested Function Evaluation and Order of Operations
Estimated Time:45s
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