January 10, 2026

Contractor Kartavya’s Conundrum / Ekalavya’s Excursions

 I’ve gone through your uploaded handwritten notes (the “Contractor Kartavya’s Conundrum / Ekalavya’s Excursions” material) and distilled them into two clean outputs:

  1. Structured study notes (crisp, exam/learning-friendly)

  2. A conceptual blog post (story-driven, intuitive, readable)

Both are derived directly from the content in the PDF, especially pages 1–5 and the later linear algebra sections on functions, matrices, inverses, and transformations .




1. Clean Notes (Structured)

Theme 1: Contractor Kartavya’s Conundrum

Problem statement

  • Kartavya wants to determine the optimal statewise distribution of workers to maximize productivity.

  • Parameters:

    • ( k = 120 ) months

    • ( n = 30 ) states

  • Productivity over time is modeled using a system of linear equations:
    [
    \begin{aligned}
    a_{11}s_1 + a_{12}s_2 + \dots + a_{1n}s_n &= P_1 \
    a_{21}s_1 + a_{22}s_2 + \dots + a_{2n}s_n &= P_2 \
    \vdots \
    a_{k1}s_1 + a_{k2}s_2 + \dots + a_{kn}s_n &= P_k
    \end{aligned}
    ]

Key idea


Theme 2: Outsourcing as Optimization

How Kartavya outsources

  1. Defines an error function

  2. Uses an iterative method metaphorically called
    “Blind man’s walk down the hill”

    • Intuition for gradient descent

    • Move step-by-step in the direction that reduces error

Insight

  • Even without deep math, arithmetic + iteration can converge to good solutions


Theme 3: Functions and Inverses (Ekalavya’s Excursions)

Scalar Functions

  • Example:
    [
    f(x) = x^2 \Rightarrow f^{-1}(y) = \sqrt{y}
    ]

  • Understanding a function deeply allows construction of its inverse


Theme 4: Matrices as Functions

A matrix behaves like a function mapping vectors to vectors.

Example:
[
f:
\begin{pmatrix}
x \ y
\end{pmatrix}
\mapsto
\begin{pmatrix}
2x + y \
x + 3y
\end{pmatrix}
]

  • This is a function ( f: \mathbb{R}^2 \to \mathbb{R}^2 )

  • Question: Is it invertible?


Theme 5: Finding the Inverse (Hook or Crook)

Solve:
[
\begin{cases}
2\alpha + \beta = a \
\alpha + 3\beta = b
\end{cases}
]

Solution:
[
\begin{pmatrix}
\alpha \
\beta
\end{pmatrix}

\begin{pmatrix}
\frac{3a-b}{5} \
\frac{2b-a}{5}
\end{pmatrix}
]

Matrix inverse:
[
\begin{pmatrix}
2 & 1 \
1 & 3
\end{pmatrix}^{-1}

\begin{pmatrix}
\frac{3}{5} & -\frac{1}{5} \
-\frac{1}{5} & \frac{2}{5}
\end{pmatrix}
]


Theme 6: Linear Combinations & Span

  • Any point in the plane can be written as:
    [
    \alpha u + \beta v
    ]

  • If vectors (u, v) are linearly independent → mapping is 1–1 and onto


Theme 7: Composition of Linear Maps

If:
[
f(x,y) = (2x+y,\ x+3y)
]
[
g(a,b) = (a+b,\ 4a+5b)
]

Then:
[
g(f(x,y)) = (3x+4y,\ 13x+19y)
]

➡️ Composition corresponds to matrix multiplication


Theme 8: Geometric Transformations

  • Rotation by 90° clockwise:
    [
    \begin{pmatrix}
    0 & 1 \
    -1 & 0
    \end{pmatrix}
    ]

  • Reflections and rotations are also linear transformations

  • Geometry ↔ algebra via matrices


2. Blog Post (Conceptual & Story-Driven)

From Blind Walks to Brilliant Solutions: How Linear Algebra Explains Learning

Kartavya isn’t a mathematician. He’s a contractor with a problem.

He has workers scattered across 30 states and productivity data spanning 120 months. The question haunting him is deceptively simple:

How should I distribute my workers so productivity is maximized?

Behind the scenes, this is a massive system of equations—far too complex to solve by hand. So Kartavya does something radical.

He outsources thinking itself.


Learning Without Knowing the Math

Kartavya defines an error—how far reality is from what he wants. Then he lets the town try random steps, keeping only those that reduce the error.

It’s like a blindfolded person walking downhill, step by step.

You already know this idea by another name: gradient descent.

Learning, it turns out, doesn’t require genius—just feedback and direction.


Ekalavya’s Real Lesson

Ekalavya asks a deeper question: What does it mean to reverse a process?

If squaring turns 3 into 9, what turns 9 back into 3?

This curiosity leads us from simple functions to matrices—objects that don’t just compute numbers, but move space itself.


Matrices Are Functions in Disguise

A matrix isn’t just numbers in a box. It’s a function:

  • It takes a point

  • Moves it

  • Stretches it

  • Rotates it

  • Or flips it

And sometimes—if you’re lucky—you can undo it perfectly.

That’s what an inverse really is:
A guarantee that no information was lost.


Why This Matters

  • Machine learning is just Kartavya’s outsourcing, scaled up

  • Neural networks are stacked matrix functions

  • Invertibility is about reversibility and trust

  • Geometry, algebra, and optimization are the same story told differently


Final Thought

Math isn’t about symbols.

It’s about control:

  • Can you predict?

  • Can you reverse?

  • Can you improve step by step?

Kartavya didn’t learn linear algebra.

Linear algebra learned Kartavya.


If you want, I can:

  • Turn this into LaTeX notes

  • Simplify it for high-school / JEE / undergrad

  • Convert the blog into Medium / Substack style

  • Add visual explanations or diagrams

Just tell me how you want to use it.