The interval in which the function f giv

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Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Relations and Functions

Question:

The interval in which the function f given by f(x) = x² - 4x + 6 is strictly increasing is

Options:

(-∞, 2)

(-∞,-2)

(2,∞)

(-2,∞)

Correct Answer:

(2,∞)

Explanation:

f(x) = x² - 4x + 6

(x) = 2x - 4

f'(x) = 0 gives us 2x - 4 = 0 or x = 2

point x = 2 divides the real line into two disjoint intervals (-∞, 2)(2, ∞)

So interval (2, ∞), f'(x) > 0

∴ f is strictly increasing in (2, ∞)