User:RDBury/Errors in MathWorld

This is a list of factual errors I've found on the MathWorld site. This is for tracking purposes to ensure these errors are fixed.
 * Strophoid
 * Formula (2), the expression for the y-coordinate, the radical term should be multiplied by m.
 * Formula (4), given as the polar equation of a general strophoid, is in fact the formula for an oblique strophoid.
 * Rule 220 and Rule 222
 * Formulas are interchanged.
 * Semicubical Parabola
 * Formula (8) for arclength is incorrect, should be 1/12 instead of 1/27. (this is assuming a=1 which is the only value that makes the numerator correct.)
 * Inverse Curve
 * In the definition in the first line, the relationship between OP and OQ is correct, but nowhere does it say that O, P and Q must be colinear, which is required.