The value of (cos θ + i sin θ)(cos θ - i sin θ) = ?
The value of (cos θ + i sin θ)(cos θ - i sin θ) = ? Correct Answer 1
Concept:
Euler's formula:
A complex number z = cos θ + i sin θ can also be written as eiθ.
Calculation:
From Euler's formula, we know that:
(cos θ + i sin θ)(cos θ - i sin θ) = (eiθ)(e-iθ) = e0 = 1.
= cos2 θ + sin2θ
= 1
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Feb 20, 2025