(a).

The limit is .

Substitute   and in the above limit.

The limit is  indeterminate.

(b).

The limit is .

Substitute   and in the above limit.

.

(c)

The limit is .

Substitute   and in the above limit.

.

(d).

The limit is .

Substitute and in the above limit.

The limit is  indeterminate.

(e).

The limit is .

Substitute and in the above limit.

(f).

The limit is .

Substitute and in the above limit.

The limit is  indeterminate.

(a).The limit is  indeterminate.

(b)..

(c)..

(d)The limit is  indeterminate.

(e).

(f).The limit is  indeterminate.