Mark the correct alternative in each of the following:

Let f : [2, ∞) X be defined by f(x) = 4x – x2. Then, f is invertible, if X =


Given that f: [2, ∞) X be defined by


f(x) = 4x – x2


Let y = f(x)


y = 4x – x2


-y + 4 = 4 - 4x + x2


4 – y = (x – 2)2




So,


where x < 4


So, x ϵ (–∞, 4]

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