# Thread: Explain Sin, Cos, and Tan of 0 degrees

1. ## Explain Sin, Cos, and Tan of 0 degrees

Hi, is it possible for someone to explain to me why the sin, cos and tan of 0 degrees is 0, 1 and 0 degrees respectively. I am a visual learner, and i just can't get my head around the concept.

Inaddition i would also like to understand why the sin cos and tan of 90 degrees is 1 degree, 0 and undefined.

Thanks in advance, =]

2. definitions you need to know ...

$\sin{\theta}= \frac{y}{r}$

$\cos{\theta}= \frac{x}{r}$

$\tan{\theta} = \frac{y}{x}$

the ray where $\theta = 0$ intersects the unit circle at the coordinates (1,0), i.e. , x = 1 and y = 0.

substitute the values of each coordinate into the definitions ... what do you get?