All GRE Subject Test: Math Resources
Example Question #162 : Imaginary Numbers
Write the complex number in polar form, that is, in terms of a distance from the origin on the complex plane and an angle from the positive -axis, , measured in radians.
To see what the polar form of the number is, it helps to draw it on a graph, where the horizontal axis is the imaginary part and the vertical axis the real part. This is called the complex plane.
To find the angle , we can find its supplementary angle and subtract it from radians, so .
Using trigonometric ratios, and .
To find the distance , we need to find the distance from the origin to the point . Using the Pythagorean Theorem to find the hypotenuse , or .