d'Alembert's Theorem
If three Circles 
, 
, and 
are taken in pairs, the external similarity points of the three pairslie on a straight line. Similarly, the external similarity point of one pair and the two internal similarity points of theother two pairs lie upon a straight line, forming a similarity axis of the three Circles.
References
Dörrie, H. 100 Great Problems of Elementary Mathematics: Their History and Solutions. New York: Dover, p. 155, 1965.
- Fourier Transform--Heaviside Step Function
- Fourier Transform Inverse Function
- Fourier Transform--Lorentzian Function
- Fourier Transform--Ramp Function
- Fourier Transform--Rectangle Function
- Fourier Transform--Sine
- Four Travelers Problem
- Four-Vector
- Four-Vertex Theorem
- Fox's H-Function
- F-Polynomial
- Frac
- Fractal
- Fractal Dimension
- Fractal Land
- Fractal Process
- Fractal Sequence
- Fractal Valley
- Fraction
- Fractional Calculus
- Fractional Derivative
- Fractional Differential Equation
- Fractional Fourier Transform
- Fractional Integral
- Fractional Part