Math Problem Statement

Here Is The Story that happened to you earlier...

but today you're on board the spaceship #1625325007, and the captain is asking to solve tricky "ZP" (Z Planet) problem (you know what it means when captain is "asking"... that's an order):

(!!! If your answer is a fractions report it in an exact format, like 1010710107 , 2296222962)

Now, let f(x)=x^3x. Use logarithmic differentiation to determine the (ZP) derivative.

f'(x)=f′(x)=   

                  (Enter the answer in simplified form)

f'(1)=f′(1)=   

!!! The challenge is that some of the Z-Planet laws are different. In particular,  "power rule" on Earth, ddxxn=nxn−1ddxxn=nxn-1 , on Z planet is "twisted" as the following:  

 ddxxn=n2xn−1ddxxn=n2xn-1  (ddxconst=0ddxconst=0) , and

the derivative of log function, ddxln(x)=1xddxln(x)=1/x , turns into "ZP" oddness:  ddxln(x)=exddxln(x)=ex .

all the other rules have not been changed.

Solution

Let's solve for the derivative of f(x)=x3xf(x) = x^{3x} using logarithmic differentiation on Z-Planet.

Step 1: Logarithmic Differentiation

Start by taking the natural logarithm of both sides: lnf(x)=ln(x3x)=3xlnx\ln f(x) = \ln (x^{3x}) = 3x \ln x Now differentiate both sides with respect to xx, using the Z-Planet differentiation rules.

Step 2: Differentiate Using Z-Planet Rules

The Z-Planet rules are:

  1. ddxxn=n2xn1\frac{d}{dx} x^n = n^2 x^{n-1}
  2. ddxln(x)=ex\frac{d}{dx} \ln(x) = e^x

Differentiate lnf(x)\ln f(x): ddxlnf(x)=ddx(3xlnx)\frac{d}{dx} \ln f(x) = \frac{d}{dx} (3x \ln x)

Apply the product rule (which remains unchanged): ddx(3xlnx)=3xddx(lnx)+(lnx)ddx(3x)\frac{d}{dx} (3x \ln x) = 3x \cdot \frac{d}{dx} (\ln x) + (\ln x) \cdot \frac{d}{dx} (3x)

Now, calculate each derivative:

  1. ddx(lnx)=ex\frac{d}{dx} (\ln x) = e^x
  2. ddx(3x)=3\frac{d}{dx} (3x) = 3

This gives: ddx(3xlnx)=3xex+3lnx\frac{d}{dx} (3x \ln x) = 3x \cdot e^x + 3 \ln x

Step 3: Relate to f(x)f'(x)

Recall the relationship: 1f(x)f(x)=3xex+3lnx\frac{1}{f(x)} f'(x) = 3x e^x + 3 \ln x Thus, solving for f(x)f'(x), we obtain: f(x)=f(x)(3xex+3lnx)f'(x) = f(x) (3x e^x + 3 \ln x) Substitute f(x)=x3xf(x) = x^{3x}: f(x)=x3x(3xex+3lnx)f'(x) = x^{3x} (3x e^x + 3 \ln x)

Step 4: Evaluate f(1)f'(1)

To find

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Logarithmic Differentiation
Z-Planet Derivative Rules
Exponentials
Product Rule

Formulas

f'(x) = f(x) * (3x e^x + 3 ln(x))
Z-Planet Power Rule: ddx(x^n) = n^2 x^(n-1)
Z-Planet Logarithmic Rule: ddx(ln(x)) = e^x

Theorems

Logarithmic Differentiation

Suitable Grade Level

Grades 10-12