Question Details

For which of the values of x, the rate of increase of the function y=3x2-2x+7 is 4 times the rate of increase of x?

Options

A

-1

B

1/3

C

1

D

0

Correct Answer :

1

Solution :

The correct option is 1.

To find the value of x for which the rate of increase of the function y is 4 times the rate of increase of x, we need to set up a relation using derivatives with respect to a variable, say time t.

Let the rate of increase of x with respect to time t be denoted by:
dxdt
And the rate of increase of y with respect to time t be denoted by:
dydt

According to the problem description, the rate of increase of the function y is 4 times the rate of increase of x. Therefore, we can write the relationship as:
dy dt = 4 dx dt

We are given the function:
y = 3 x2 - 2 x + 7

Differentiating both sides of the function with respect to t using the chain rule, we obtain:
dy dt = d dt 3 x2 - 2 x + 7

Applying the differentiation rules:
dy dt = 6 x - 2 dx dt

Now, we substitute the relationship dydt=4dxdt into our differentiated equation:
4 dx dt = 6 x - 2 dx dt

Assuming that the rate of change of x is non-zero (i.e., dxdt0), we can divide both sides by dxdt:
4 = 6 x - 2

Solving for x:
Add 2 to both sides of the equation:
4 + 2 = 6 x
6 = 6 x
Divide by 6:
x = 1

Thus, the rate of increase of the function is 4 times the rate of increase of x when x = 1.

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