How do you write #3[(cos(pi/10) + i sin (pi/10)]# in rectangular form?

1 Answer
Feb 12, 2016

(2.853, 0.9271) or, explicitly, 2.853 + i 0.9271,

Explanation:

In rectangular form of a complex number, with real part x and imaginary part y, we use the ordered pair (x, y) to represent the complex number x + i y. Converting to polar coordinates,, using #x = r cos(theta) and y = r sin(theta)#,, it becomes (r, #theta) = r ( cos(theta) + i sin(theta)). Here, r = 3 and theta = pi/10 = 18 deg #