Saturday

October 25, 2014

October 25, 2014

Posted by **Elli** on Monday, December 19, 2011 at 9:14pm.

Consider the function f(x) = (0.1x-1)(x+2)^2.

a) Determine the function's average rate of change on -2<x<6.

Answer; Avg rate of change is -3.2

b) Estimate the instantaneous rate of change at x=2.

Answer -4.7999

c) Explain why the rates of change in parts a) and b) have been negative

d) Give an interval on which the rate of change will be increasing?

- Math -
**Steve**, Tuesday, December 20, 2011 at 4:40amf(x) = .1(x-10)(x+2)^2

So, it has a double root at x = -2 and another root at x = 10.

Since it's a cubic, with positive coefficient for x^3, it rises from the left, brushes against the x-axis at x = -2, decreases and comes back to cross again at x=10.

f is decreasing at the places of interest.

Any interval where x > 10 will have f increasing. Since you ask about instantaneous changes, I assume you know about derivatives.

f' = .1 ( 3x^2 - 12x - 36 )

f' = 0 at x = -2 and 6

So, f is increasing for x < -2 and x > 6

**Answer this Question**

**Related Questions**

Math~Reinyyy - Could someone help me with these questions, I don't know ...

Math - Verify if question a is correct I calcuated twice now and I am getting 0 ...

Calulus - Consider the following function. f(t) = 3t2 − 3 (a) Find the ...

Calculus - I have a couple of questions and i wanted to know if my answers are ...

math - A function is given below. Determine the average rate of change of the ...

College algebra! - For the linear function f(x) = 5x + 3 (a) Determine the slope...

Algebra - A function is given. Determine the average rate of change of the ...

college algebra - A function is given. Determine the average rate of change of ...

college algebra - A function is given. Determine the average rate of change of ...

function rate of change - Joe is investigating the rate of change of the ...