How do you find the standard notation of #5(cos 210+isin210)#?

1 Answer
Gió
Feb 7, 2015

I suppose you want this complex number in the #a+ib# form.

You have only to evaluate your #cos# and #sin# and do the nultiplication by 5:

#5[cos(210°)+isin(210°)]=#
#=5cos(210°)+5isin(210°)=#
#=5(-sqrt(3)/2)+5i(-1/2)=#
#=-5sqrt(3)/2-5/2i#

Which is in the form: #a+ib#

If you want you can evaluate the square root and the divisions but I would leave it like it is.

hope it helps

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