<p>when you are taking the partial derivative of the Lagrangian wrt l you are taking the other variables as constants, so they are derived away. You cannot do this with f(k,l) as this is a function with a l input</p>
<p>the same applies to the partial derivative of the Lagrangian wrt k</p>
<p>refer back to the rules of partial differentiation</p>

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2023-10-28T10:52:44.513Z
2023-10-28T10:52:44.513Z
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<p>Guys in the following optimisation problem why are we not considering the partial derivate of K and L in the Lagrangian in the first two equations</p>

<macroeconomics><microeconomics><mathematical-economics>
Cost Minimization
user205152
# Cost Minimization

(Asked by: username_0 on 2023-10-27)

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Guys in the following optimisation problem why are we not considering the partial derivate of K and L in the Lagrangian in the first two equations

**Tags:** macroeconomics, microeconomics, mathematical-economics

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## 1 answers

### Answer by username_1 on 2023-10-28. Score: 1

when you are taking the partial derivative of the Lagrangian wrt l you are taking the other variables as constants, so they are derived away. You cannot do this with f(k,l) as this is a function with a l input

the same applies to the partial derivative of the Lagrangian wrt k

refer back to the rules of partial differentiation


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