Which of the following is a fourth root of ?
Explanation for the correct option:
Step 1: Change the equation into polar form
Complex equation
Let ….(1)
Therefore, and
Polar form ….(2)
Now
and
Equate equation(1) and equation(2),
Step 2: Write the equation in exponential form
The exponential form of a complex number is .
The fourth root of the equation is,
Step 3: Write the equation in cis from
We know that,
Hence, the correct option is option (a).