Math Problem Statement

. (a) Using Chain Rule, find (dz)/(dt) dagger the function z = sqrt(1 - x + 4x * y ^ 2) x = ln(t) y = t ^ (3/2)

Solution

We are given the function z=1x+4xy2z = \sqrt{1 - x + 4xy^2}, where x=ln(t)x = \ln(t) and y=t3/2y = t^{3/2}, and we need to find dzdt\frac{dz}{dt} using the chain rule.

Step 1: Differentiate zz with respect to tt using the Chain Rule

The Chain Rule tells us: dzdt=zxdxdt+zydydt\frac{dz}{dt} = \frac{\partial z}{\partial x} \frac{dx}{dt} + \frac{\partial z}{\partial y} \frac{dy}{dt}

Step 2: Compute the partial derivatives of zz

First, rewrite zz for clarity: z=(1x+4xy2)1/2z = (1 - x + 4xy^2)^{1/2}

  • The partial derivative of zz with respect to xx: zx=12(1x+4xy2)1/2(1+4y2)\frac{\partial z}{\partial x} = \frac{1}{2}(1 - x + 4xy^2)^{-1/2}(-1 + 4y^2)

  • The partial derivative of zz with respect to yy: zy=12(1x+4xy2)1/2(8xy)\frac{\partial z}{\partial y} = \frac{1}{2}(1 - x + 4xy^2)^{-1/2}(8xy)

Step 3: Compute the derivatives of xx and yy with respect to tt

  • The derivative of x=ln(t)x = \ln(t) with respect to tt: dxdt=1t\frac{dx}{dt} = \frac{1}{t}

  • The derivative of y=t3/2y = t^{3/2} with respect to tt: dydt=32t1/2\frac{dy}{dt} = \frac{3}{2}t^{1/2}

Step 4: Combine everything

Now substitute these derivatives into the Chain Rule formula: [ \frac{dz}{dt} = \left[\frac{1}{2}(1 - x + 4xy^2)^{-1/2}(-1 + 4y^2)\right] \cdot \frac{1}{t} + \left[\frac{1}{2}(1 - x + 4xy^2)^{-1/2}(8xy)\right] \cdot \frac{3}{2}t^{1/2} ]

This is the expression for dzdt\frac{dz}{dt}, which can be simplified further, but it is now set up in terms of tt.

Would you like me to simplify this further or explain any part in detail?


Here are 5 related questions to further your understanding:

  1. How does the chain rule apply to functions of several variables?
  2. What is the physical significance of partial derivatives in multivariable calculus?
  3. Can we use implicit differentiation in this problem, and how would it affect the result?
  4. How does logarithmic differentiation help in solving derivatives involving logarithmic functions?
  5. How can this problem be extended to higher-order derivatives?

Tip: When solving problems involving multiple variables, always make sure to correctly apply the chain rule, carefully differentiating each variable and considering how they depend on each other.

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Math Problem Analysis

Mathematical Concepts

Multivariable Calculus
Partial Derivatives
Chain Rule

Formulas

Chain Rule: dz/dt = (∂z/∂x)(dx/dt) + (∂z/∂y)(dy/dt)
Partial derivative of z with respect to x: ∂z/∂x = (1/2)(1 - x + 4xy^2)^(-1/2)(-1 + 4y^2)
Partial derivative of z with respect to y: ∂z/∂y = (1/2)(1 - x + 4xy^2)^(-1/2)(8xy)

Theorems

Chain Rule for multivariable functions

Suitable Grade Level

Undergraduate Calculus