Dave Richeson on X: "Euler proved that π/4=arctan(1/2)+arctan(1/3), which can be used for computing digits of π (using the arctangent series). I wondered if I could prove it without using a trig
![SOLVED: CALCULATION OF THE VOLUME: 1. Block V=l w h 2. Cube V=e^3 3. Cylinder V=(π)/(4) D^2 h 4. Sphere V=(π)/(6) D^3 SOLVED: CALCULATION OF THE VOLUME: 1. Block V=l w h 2. Cube V=e^3 3. Cylinder V=(π)/(4) D^2 h 4. Sphere V=(π)/(6) D^3](https://cdn.numerade.com/ask_images/d63ef184-f895-409d-a0ce-b070e8e8e089.jpg)
SOLVED: CALCULATION OF THE VOLUME: 1. Block V=l w h 2. Cube V=e^3 3. Cylinder V=(π)/(4) D^2 h 4. Sphere V=(π)/(6) D^3
![integration - Find the value of the integral: $\int_{0}^{\frac{\pi}{4}} \frac{1}{3\cos^2\theta + \sin^2\theta}d\theta$ - Mathematics Stack Exchange integration - Find the value of the integral: $\int_{0}^{\frac{\pi}{4}} \frac{1}{3\cos^2\theta + \sin^2\theta}d\theta$ - Mathematics Stack Exchange](https://i.stack.imgur.com/Ccev5.png)