#### To determine

**(a)**

**To explain:**

The meaning of f is differentiable at a.

#### Answer

f is differentiable at a, means the derivative of function at point x = a exists.

#### Explanation

The derivative of a function f at point a in its domain is given by,

f'a= limh→0fa+h-f(a)h

Now f is differentiable at a, if the limit given by f'a exists.

#### To determine

**(b)**

**To explain:**

Relation between differentiability and continuity of a function.

#### Answer

if a function is differentiable at point x =a, then it is continuous at x = a.

#### Explanation

The function f is differentiable if derivative of that function exists. All differentiable functions are continuous but not all continuous functions are differentiable.

#### To determine

**(c)**

**To sketch:**

The graph of function continuous but not differentiable at a = 2.

#### Answer

#### Explanation

From the graph, y = |a - 2| is continuous but not differentiable at a = 2.