How do you simplify expressions with imaginary numbers?

Such as:
#i^15#
or
#(25+17i)-(-23-18i)#

1 Answer
Apr 26, 2018

Explanation

Explanation:

#i^2=-1# since #i=\sqrt(-1)#
#i^15=i^(2(7)+1)=(i^2)^7(i)=(-1)^7(i)=-1(i)=-i#

Treat the #i# like a variable in the second case, but don't solve for it since it already has a value.
#(25+17i)-(-23-18i)#
#25+17i+23+18i# (simplify signs)
#48+35i# (add like terms)