Question

If g(x) = x^2-5, find the value(s) of x so that:
a. g(x)= 20
b. g(x) = 6

Answer 1

9514 1404 393

Answer:

  a)  x = ±5

  b)  x = ±√11 ≈ ±3.317

Step-by-step explanation:

Since we want x for some function value, it is convenient to determine the inverse function.

  x = g(y)

  x = y^2 -5

  x +5 = y^2

  y = ±√(x +5)

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a) x = ±√(20 +5) = ±5

b) x = ±√(6 +5) = ±√11 ≈ ±3.317