Article contents
A Functional Equation Characterising the Sine
Published online by Cambridge University Press: 03 November 2016
Extract
Recent articles on equations characterising the trigonometric functions ([1], [2]) prompt a consideration of still another equation, which might be classified under the heading of “Students’ Mathematical Mythology” In [3], Mr. Heafford multiplies the “obvious” sin (x + y) = sin x + sin y by the equally “clear” sin (x − y) = sin x − sin y to obtain the (correct!) result, sin (x+y) sin(x − y) = sin2x − sin2y.
- Type
- Research Article
- Information
- Copyright
- Copyright © Mathematical Association 1960
References
- 6
- Cited by