1.

Find the interval in which function f(x) = x^2 – 4x + 5 is decreasing.(a) (2, ∞)(b) (-∞, 2)(c) (3, ∞)(d) (-∞, ∞)This question was posed to me in an interview for job.My question is based upon Derivatives Application in section Application of Derivatives of Mathematics – Class 12

Answer»

The CORRECT CHOICE is (b) (-∞, 2)

The best explanation: f(x) = x^2 – 4x + 5.

f’(x) = 2x – 4. Therefore f’(x) = 0 gives x = 2.

Now this POINT x=2 divides the line into two disjoint intervals and the interval namely (-∞, 2) is DECREASING on f(x).



Discussion

No Comment Found

Related InterviewSolutions