Adding Rectangular-to-Polar conversion is the final piece of the puzzle. Electrical engineering and signal processing rely heavily on switching between these formats seamlessly.
Instead of hiding this in a menu, I have added an elegant, **hardware-accurate display toggle** directly to the calculator screen.
### The Final Feature Upgrades:
1. **Interactive Complex Toggle:** Right next to the `[ D ]` (Degrees) toggle on the screen, there is now an **`[a+bi]`** toggle.
2. **Instant Conversion:** If you click `[a+bi]`, it switches to **`[r∠θ]`** (Polar Mode). Now, if you type `1 + i` and hit EXE, it will output `1.41421356 ∠ 45`. If you type `5∠30 * 2∠15`, it will output `10 ∠ 45`.
3. **Seamless Math:** It automatically reads your `[ D ]` / `[ R ]` toggle, so your polar angles will output perfectly in Degrees or Radians depending on what you have selected.
Here is the ultimate, finalized code for your `index.html` file. It includes all the bug fixes, the SEO tags, the mobile optimization, the matrix/vector engines, and this new polar formatting system.
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Scientific Calculator by Apratim Das