trig form to complex number form

[corsec]

I"m really stumped on this thing does anyone have any ideas?

10(cos(2pi/3) + i sin(2pi/3))

i is imaginary of course but i'm puzzled on how to begin to transform this into an equivalent trig form.






edit: rewrote equation

 

[daon]

I"m really stumped on this thing does anyone have any ideas?

10(cos(2pi/3) + isin(pi/2))

i is imaginary of course but i'm puzzled on how to begin to transform this into an equivalent trig form.

10(-1/2 + i)
= -5 + 10i

This is helpful to find powers. i.e.
(-5 + 10i)^n = 10^n(cos(2npi/3) + isin(npi/2))

Is that your question?

 

[corsec]

that sort of answers it, the entire concept of transforming it to a trig form from complex is confusing me.

actually let me rewrite it because I wrote it wrong

10(cos(2pi/3)) + i sin(2pi/3))

 

[daon]

that sort of answers it, the entire concept of transforming it to a trig form from complex is confusing me.

actually let me rewrite it because I wrote it wrong

10(cos(2pi/3)) + i sin(2pi/3))

I knew something was odd. Anyway, same concept. Cos(2pi/3) = -1/2, Sin(2pi/3) = sqrt(3)/2, so

= 10(-1/2 + sqrt(3)i/2) = -5 + 5sqrt(3)i

Just evaluate the sines and cosines, substitute and distribute. Nothing to it.

 

[corsec]

that helped me more than an entire chapter of 2 text books! thank you.