# Lagrange Multiplier problem

I'm in a bit of a hurry, so this isn't going to be very pretty.

## Homework Statement

Maximize: V(l,d) = pi * (0.5*d)^2 * l
Subject to: l + 3.5d = 84 -> C(l, d) = l + 3.5d - 84

## Homework Equations

∇V(l,d) = λ ∇C(l,d)

## The Attempt at a Solution

∇V(l,d) = 0.5*pi*d
∇C(l,d) = 0

How do I find the Lagrange multiplier if the gradient of the condition-function is 0? I have to find the optimal conditions using Lagrange's method. I have already found the optimal conditions using the method involving elimination of variables, which gave me l = 28 and d = 26. Now I have to get the same results using this method.

EDIT: Nevermind. I figured out my stupid mistake.

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