# Find the length of curve r=1-cos (tita)

1. Jul 15, 2006

### teng125

find the length of curve r=1-cos (tita)

pls help to formulat an eqn for f(x,y)

thanx

2. Jul 15, 2006

### nazzard

Hello teng,

the curve is given in polar coordinates.

$$\theta \, \mapsto \, (r(\theta)\cos(\theta),r(\theta)\sin(\theta))$$

with $$\theta_1\leq\theta\leq\theta_2$$

You can make use of the appropriate formula to calculate the length L.

$$L=\int_{\theta_1}^{\theta_2}\sqrt{(r'(\theta))^2+r^2(\theta)} \, d\theta$$

Regards,

nazzard

Last edited: Jul 15, 2006