How do you write 3i in trigonometric form?

1 Answer
Gió
Jun 8, 2016

I found: z=3i=3[cos(90∘)+isin(90∘)]

Explanation:

We can find the position of your number on the complex plane:
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We have that:
z=3i=ρ[cos(θ)+isin(θ)] in trigonometric form, where:
ρ= modulus, the distance from the origin to your point; in this case: ρ=3
θ= angle with the horizontal Real positive semi-axis; in this case: θ=90∘.
So you get:
z=3i=3[cos(90∘)+isin(90∘)]

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