Euler's Formula (e^(iθ) = cos θ + i sin θ)

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e^(iθ) = cos θ + i sin θ

What each symbol means

SymbolWhat it stands for
θReal angle in radians (usual convention in JEE)
e^{iθ}Point on unit circle at angle θ from positive real axis

When to use this

θ ∈ ℝ. Extends polar form: z = re^(iθ) with r = |z|, θ = arg z.