1. Apr 28, 2005

### chandran

Radians have the very nice property that $$lim_{x->0}\frac{sin x}{x}$$= 1[/tex] and $$lim_{x->0}{1- cos x}{x}= 1$$ when x is in radians. As a result the derivative of sin x is cos x and the derivative of cos x is -sin x as long as x is in radians. That's not true if x is measured in degrees. If we insist upon using degrees the corresponding derivatives would be multiplied by $$\frac{180}{\pi}$$.