Parametric equations for the tangent line

[Whatupdoc]

Find parametric equations for the tangent line at the point (cos(-4pi/6),sin(-4pi/6),-4pi/6) on the curve x=cost, y=sint,z=t

x(t) = _________
y(t) = _________
z(t) = _________

r'(t) = <-sin(t), cos(t), 1>
r'(0) = <0,1,1>



my answer:
x = cos(-4pi/6) + 0t
y = sin(-4pi/6) +1t
z = -4pi/6 +t

the only part i got correct is the z, anyone know what I am doing wrong?

 

[StatusX]

You want the derivative at the tangent point, not t=0.

 

[Whatupdoc]

yea your right, i don't know what i was thinking, thanks