A few days ago
Anonymous

Calculus Derivatives???

Need help on these problems… can’t figure out how to do this…I would really appreciate if anyone can help me out and give me details on how to do these problems…(Show how you did it)…

1. When x = 4, the function is f(x) = [x(x-3)]^4.

2. Find the slope of the line that is tangent to the graph of the function f(x) = 4ln(3x) – 5x, when x = 4.

3. Given the function f(x)= 3x^(3)e^(3x), what is the instantaneous rate of change at x = 1

4. Find the derivative of g(x) = x ln(2x – 5) + 9x – 10, when x=4. Keep answer exact.

Thanks in advance…

Top 1 Answers
A few days ago
Ipsulis

Favorite Answer

I don’t understand what the first question is asking for.

What you will need for the other three questions:

1. If g(x) = kx^j where k and j are constants,

g ‘ (x) = j*k*x^(j-1)

2. If g(x) = ke ^ f(b) where k is a constant and f(b) is a function,

g ‘ (x) = k* f ‘ (b) e ^ f(b)

3. If g(x) = k ln f(b) where k is a constant and f(b) is a function,

g'(x) = k * f ‘ (b) * 1 / f(b)

4. if g(x) = h(x) * j(x) where h(x) and j(x) are functions,

g ‘ (x) = h(x) * j ‘ (x) + h ‘ (x) * j(x)

This information is all you need to know to solve these problems. If you have any other questions, just edit your current question and I will check back tomorrow.

I will do one sample problem for you:

Problem 3: f(x) = 3x^(3) * e^(3x)

Step 1: Replace 3x^(3) with h(x) and e^(3x) with j(x)

h(x) = 3x^3

j(x) = e^(3x)

f(x) = h(x) * j(x)

Step 2: Find h ‘ (x) and j ‘ (x)

h ‘ (x) = 9x^2 Using RULE 1

j ‘ (x) = 3e^(3x) Using RULE 2

Step 3: Enter h(x), j(x), h ‘ (x), and j ‘ (x) into RULE 4’s equation.

f ‘ (x) = h(x) * j ‘ (x) + h ‘ (x) * j (x)

f ‘ (x) = 3x^3 * 3e^ (3x) + 9x^2 * e^(3x)

Step 4: Now that you have the equation for the slope of the line on any x, plug in x = 1 into your new equation

f ‘ (1) = 3 * 1^3 * 3e^(3*1) + 9 * 1^2 * e^(3*1)

Step 5: Simplify, and the result is your answer

f ‘ (1) = 18 e ^ 3

0