Question Details

The function defined by f(x) = 4⁴ – 2x + 1 is increasing for

Options

A

x < 1

B

x > 0

C

x < 1/2

D

x > 1/2

Correct Answer :

x > 1/2

Solution :

The correct option is x > 1/2.

To understand why this is correct, we analyze the given function. The expression in the question, written as f(x)=4x2-4x+1 (which can also be written in its factored form as the perfect square (2x-1)2), represents a quadratic function.

A function is increasing on an interval where its first derivative is positive, i.e., where:
f(x)>0

First, we find the derivative of f(x) with respect to x using the power rule:
f(x)=ddx(4x2-4x+1)
f(x)=8x-4

Next, to determine the interval where the function is increasing, we set the first derivative to be greater than zero:
8x-4>0

Solving this inequality for x:
8x>4
x>48
x>12

Thus, the function is strictly increasing for the interval x > 1/2.

Unlock Our Free Library

Access expert-curated educational resources and study materials—completely free.

Discover more resources

You may also like

Mock Tests

View All
  • JEE
  • intermediate
  • 3 hours
  • chemistry, mathematics, physics

  • JEE
  • intermediate
  • 3 hours
  • chemical engineering, mathematics, physics