$\"\"$

The statement is $\"\"$ .

Condition I:

First show that, the above formula is true, when $\"\"$ .

When $\"\"$ , the formula is $\"\"$ .

Condition 1 of the Principle of Mathematical Induction holds.

$\"\"$

Condition II:

Assume that $\"\"$ holds for some $\"\"$ , and determine whether the formula then holds for $\"\"$ .

Assume that, $\"\"$ for some $\"\"$ .

Now need show that,

$\"\"$

It follows that,

$\"\"$

Condition II also holds good.

The statement is true for all natural numbers.

$\"\"$

The statement is true for all natural numbers.