MonotonicityHard
Question
In which interval f(x) = 2x2 - ln | x |, (x ≠ 0) is monotonically decreasing-
Options
A.(-1 / 2, 1 / 2)
B.(-∞, -1 / 2)
C.(-∞, -1 / 2) υ (0, 1/2)
D.(-∞, -1 / 2) υ (1/2, ∞)
Solution
f(x) = 2x2 - log | x | (x ≠ 0)
f(x) = 2x2 - log | x | f′(x) = 4x -
< 0
< 0, 
< 0
(-∞, -1/2 ) υ (0, 1/2)
f(x) = 2x2 - log | x | f′(x) = 4x -
< 0 < 0, < 0 (-∞, -1/2 ) υ (0, 1/2)Create a free account to view solution
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