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COMEDK20269 May 2026Morning ShiftMathematicsApplication of DerivativesActual

The behaviour of the function f(x) = (2x + 4 ) on ( 3 8 , 5 8 ) is:

Options

  1. AStrictly increasing on ( 3 8 , 5 8 )
  2. BStrictly decreasing on ( 8 , 5 8 )
  3. CStrictly increasing on ( 8 , 3 8 )
  4. DStrictly decreasing on ( 3 8 , 5 8 )

Correct answer

D. Strictly decreasing on ( 3 8 , 5 8 )

Step-by-step solution

Given f(x) = (2x + 4 ) Differentiating with respect to x , we get: f'(x) = 2 (2x + 4 ) For the given interval x ( 3 8 , 5 8 ) : 3 4 3 4 + 4 In the interval ( , 3 2 ) , the cosine function is negative. Therefore, (2x + 4 ) Hence, f(x) is strictly decreasing on ( 3 8 , 5 8 ) . Answer: Strictly decreasing on ( 3 8 , 5 8 )

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