How do you simplify (8+6i)(2+3i)?

1 Answer
Oct 23, 2016

35(cos(0.464)+isin(0.464))

Explanation:

First simplify Cartesian form,
(8+6i)(2+3i)=82+6i3i
=6+3i

now to convert to trigonometric form,

6+3i=rcis(θ)

where,
r=62+32
r=45 (which can be further simplified to 35)

and,

θ=tan1(36)

θ=0.464 (3dp, radians)

so we can express (8+6i)(2+3i) as,

35cis(0.464)

or in expanded version,
35(cos(0.464)+isin(0.464))