Express the complex number in trigonometric form -6+6√3i
\[-6+\sqrt{3}i\]
What are x, and y in the expression? Recall: x + iy is a form of an imaginary number.
\[-6+6\sqrt{3}i\] sorry, i mistyped it
Arent they just coordinates?
doesn't matter, the same question, what are x, y?
(-6, 6√3)?
not that, take steps, please. you have x = -6, y = 6sqrt 3 now find r, \(r^2 = x^2 +y^2\) show me r = ??
r=12?
yup, now, find \(\theta\) \(tan\theta = \dfrac{y}{x}=??\)
-30
I got -60
i re-did it to make sure
ok, take your time, tag me after you get the answer
Oh im sorry i had switched x and y
-60 = 2pi/3 I think i remember the equation now
nope, you have to have a logic to switch -60 to 2pi/3
because |dw:1407542918920:dw|
omg why do i keep making these little mistakes
Actually, the answer is 2pi/3, but you must put some argue on that to make the solution is perfect correct.
\[12(\cos \frac{ 5\pi }{ 3 }+isin \frac{ 5\pi }{ 3})\]
wait what...
That is the wrong one!!
So 2pi/3 is right? I'm a little confused
No confuse, =\(tan \dfrac{5\pi}{3}=tan\dfrac{2\pi}{3}= -\sqrt3\) We pick 2pi/3 because the given x = \(\color{red}{-~}6\) so that the terminal point must be in quadrant 2.
That give us the final answer is \(12(cos\dfrac{2\pi}{3}+isin\dfrac{2\pi}{3}\)) got what I mean??
|dw:1407543393273:dw|
Tan=5pi/3=tan2pi/3? so why choose one over the other?
because x = -6 , y = +6sqrt3 x <0, y>0 , the point is in quadrant 2 |dw:1407543518132:dw|
OHHHHH
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