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sin(87 degrees) = 0.999
Problem: find three solutions to z^3=-1. DeMoivre's theorem is that (cos b + i sin b)^n = cos bn + i sin bn So we can set z= (cos b + i sin b), n = 3 cos bn + i sin bn = -1. From the last equation, we know that cos bn = -1, and sin bn = 0. Three possible solutions are bn=pi, bn=3pi, bn=5pi. This gives three possible values of b: b=pi/3 b=pi b = 5pi/3. Now using z= (cos b + i sin b), we can get three possible cube roots of -1: z= (cos pi/3 + i sin pi/3), z= (cos pi + i sin pi), z= (cos 5pi/3 + i sin 5pi/3). Working these out gives -1/2+i*sqrt(3)/2 -1 -1/2-i*sqrt(3)/2
Exponential form is similar to 'polar form'. Call the Magnitude A, and the angle θ .Then the number is represented as A*eiθ (θ in radians). To convert to rectangular form, use Euler's formula:eiθ = cos(θ) + i*sin(θ)So the complex number A*eiθ = A*cos(θ) + A*i*sin(θ)
In a right triangle, the sine of an angle (abbreviated SIN) represents a ratio between the lengths of the side opposite of the angle and the hypotenuse of the triangle. For example, in a standard 3, 4, 5 right triangle, the 2 legs are length 3 and 4, while the hypotenuse (always the longest side) is 5.