,
where 
and 
correspond
to the values of x(t) and y(t) at the point t = 1.
at the point
Solution :
The equation of the tangent has the form
,
where
and correspond
to the values of x(t) and y(t) at the point t = 1.
Thus, 
and 
.
Now,
.
Therefore, 
.
Answer : 
.
by es