Step 1:

(a).

Standard form of a complex number is

Multiply the numerator and denominator by

Standard form of is

(b) The complex number is .

Consider .

Write the complex number in polar form.

Magnitude is and argument .

Polar form of a complex number is .

Substitute in above form.

De Moivres theorem:

If is a complex number, then ,

Where is a positive integer.

Find using De Moivres theorem,.

solution:

(a) Standard form of is

(b) Standard form of is