_{We have,}

Now, by multiplying numerator and denominator by 1 + 2i we get:

=

=

=

= - 1 + i

Let us assume and

Now by squaring and adding the given values, we get:

We know that,

∴ r² = 2

As conventionally r > 0, thus

Also,

As lies in the 2^nd quadrant

∴

Hence,

=

=

This is the required polar form of the given equation