Re: parametric: x = cos(t), y = sin(t)

Daniel C. Bastos wrote:
> In article <mYednSPOcuujw8banZ2dnUVZ_urinZ2d@[EMAIL PROTECTED]
>,
> Darrell wrote:
> 
>> Daniel C. Bastos wrote:
>>
>>>> Going back to an angle in standard position, as previously explained,

>>>> would you say an angle of 360deg is equivalent to and angle of 0?  Or
to 
>>>> an angle of -360deg?
>>> Both equivalent to zero.
>> In the same spirit, would you say any two graphs of a unit circle have 
>> equivelent paremetric equations?
> 
> Hm, I think so. If they represent the same graph, they must satisfy the
> same pairs (x, y). So they must be equivalent.

Consider these two (different) pairs of parametric equations.

a) x = t
    y = 3t - 2


b) x = t - 3
    y = 3t - 11

Find their rectangular equations:

a) y = 3x - 2   ...simple substitution

b) 3(x = t - 3)
    -(y = 3t - 11)

add:
    3x =  3t - 9
    -y = -3t + 11
  -----------------
  3x-y =        2
    -y = -3x + 2
     y =  3x - 2


-- 
Darrell