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For the function f(x)=x44−2x3+112x2−6xf(x) = \frac{x^4}{4} - 2x^3 + \frac{11}{2}x^2 - 6x, which of the following statements are TRUE?

(A) Critical points of f(x)f(x) are x=1,2x = 1, 2 and 33.

(B) f(x)f(x) is increasing over (1,2)(1,2).

(C) f(x)f(x) is decreasing over (2,3)(2,3).

(D) f(x)f(x) is increasing over (3,∞)(3,\infty).

Choose the correct answer from the options given below:

Solution

✅ Correct Option: 3

f′(x)=x3−6x2+11x−6=(x−1)(x−2)(x−3)f'(x) = x^3 - 6x^2 + 11x - 6 = (x-1)(x-2)(x-3), so critical points are 1, 2, 3. The sign of f′f' is positive on (1,2)(1,2), negative on (2,3)(2,3) and positive on (3,∞)(3,\infty). All four statements hold.

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