The vector valued function is
.
(a)
\Find
.
Substitute
in the vector function.

.
(b)
\Find
.
Substitute
in the vector function.

is not defined.
Hence
is not defined.
(c)
\Find
.
Substitute
in the vector function.

.
(d)
\Find
.
First find
.
Substitute
in the vector function.


Find
.
Substitute
in the vector function.


Now 

.
(a)
.
(b)
is not defined.
(c)
.
(d)
.