Do While Abs(x1 - x0) > tolerance fx0 = Application.Run(FunctionName, x0) fx0_plus_delta = Application.Run(FunctionName, x0 + delta) derivative = (fx0_plus_delta - fx0) / delta x1 = x0 - fx0 / derivative x0 = x1 Loop He linked it to his volatility model—a user-defined function named PriceError() that returned the difference between the market price and the model price.

He ran it.

He double-clicked. The PDF was short—only seven pages—but it was beautiful. Page one had a diagram: a curved function, a tangent line kissing the x-axis, and an arrow labeled xₙ₊₁ = xₙ − f(xₙ)/f’(xₙ) .

Arjun leaned back. The PDF lay open on his second monitor. He realized the file wasn't just a tutorial. It was a key. For years, he had treated Excel like a glorified calculator. Now, he saw it as a numerical engine. The Newton Raphson method wasn't about roots—it was about control. It was about telling the computer, “Here is the rule. Now find the truth.”

At 7:55 AM, he emailed Helena the results. He attached a clean sheet with one button: “Calculate Vol.” He didn’t tell her about the PDF. He didn’t mention the cold coffee or the 11:47 PM panic.

Arjun stared at the blinking cursor in the VBA editor. It was 11:47 PM. The spreadsheet, “Q3_Revenue_Forecast.xlsx,” was a mess of circular references and manual guesswork. His boss, Helena, needed the implied volatility of a client’s derivative portfolio by 8:00 AM, and the analytical solution was a ghost—impossible to isolate.

0.25 → 0.35 → 0.42 → 0.197 → 0.203 → 0.19999.

“You can’t solve for ‘x’ if it’s on both sides of the equation,” he muttered, sipping cold coffee.

How To Code The Newton Raphson Method In Excel Vba.pdf May 2026

He ran it.

0.25 → 0.35 → 0.42 → 0.197 → 0.203 → 0.19999. The PDF was short—only seven pages—but it was beautiful

“You can’t solve for ‘x’ if it’s on both sides of the equation,” he muttered, sipping cold coffee.

To Serve Man, with Software

I didn’t choose to be a programmer. Somehow, it seemed, the computers chose me. For a long time, that was fine, that was enough; that was all I needed. But along the way I never felt that being a programmer was this unambiguously great-for-everyone career field with zero downsides.

Here’s The Programming Game You Never Asked For

You know what’s universally regarded as un-fun by most programmers? Writing assembly language code. As Steve McConnell said back in 1994: Programmers working with high-level languages achieve better productivity and quality than those working with lower-level languages. Languages such as C++, Java, Smalltalk, and Visual Basic have been credited

Catastrophic error: User attempted to use program in the manner program was meant to be used. Options 1) Erase computer 2) Weep

Doing Terrible Things To Your Code

In 1992, I thought I was the best programmer in the world. In my defense, I had just graduated from college, this was pre-Internet, and I lived in Boulder, Colorado working in small business jobs where I was lucky to even hear about other programmers much less meet them. I

Launching The Rural Guaranteed Minimum Income Initiative

It's been a year since I invited Americans to join us in a pledge to Share the American Dream: 1. Support organizations you feel are effectively helping those most in need across America right now. 2. Within the next five years, also contribute public dedications of time or

The Road Not Taken is Guaranteed Minimum Income

The dream is incomplete until we share it with our fellow Americans.

Let's Talk About The American Dream

A few months ago I wrote about what it means to stay gold — to hold on to the best parts of ourselves, our communities, and the American Dream itself. But staying gold isn’t passive. It takes work. It takes action. It takes hard conversations that ask us to confront

Stay Gold, America

We are at an unprecedented point in American history, and I'm concerned we may lose sight of the American Dream.

Related posts