How can you use trigonometric functions to simplify # 21 e^( ( pi)/2 i ) # into a non-exponential complex number?
1 Answer
Mar 3, 2016
Explanation:
There is this identity which is very useful.
#r e^{i theta} = r (cos theta + i sin theta)#
In this case,
#r = 21#
#theta = pi/2#
So plugging the values in
#21 e^{i pi/2} = 21 (cos (pi/2) + i sin (pi/2))#
#= 21 ((0) + i (1))#
#= 21 i#
