Question Details

Find the intervals in which f(x) = 2x² – 3x is increasing

Options

A

(-1/4, ∞)

B

(-3/4, ∞)

C

(1/4, ∞)

D

(3/4, ∞)

Correct Answer :

(3/4, ∞)

Solution :

The correct option is (3/4, ∞).

To find the intervals in which the function f(x)=2x23x is increasing, we need to determine where its first derivative is strictly positive (i.e., f(x)>0).

Step 1: Find the derivative of the function.
Using the power rule of differentiation, we find f(x):
f(x)=ddx(2x23x)=4x3

Step 2: Set up the inequality for an increasing function.
A function is increasing on an interval where its derivative is positive:
f(x)>0
Substituting the derivative we found:
4x3>0

Step 3: Solve the inequality for x.
Add 3 to both sides of the inequality:
4x>3
Divide both sides by 4:
x>34

Thus, the function is increasing for all values of x greater than 34.
In interval notation, this is represented as (3/4, ∞).

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