A Visual Proof of the Cauchy-Schwarz Inequality in 2D
This illustrates the Cauchy-Schwarz inequality in two dimensions, which states:[more]
The gray area on the left is . The same gray area in the right hand image is . For , , hence the inequality.[less]
This image is from S. H. Kung, "Proof without Words: The Cauchy-Schwarz Inequality," Mathematics Magazine, 81(1), 2008 p. 69.