Imaginary numbers — are they merely numbers that “exist only in the mind of the mathematician”?

Introduction / Context:
This statement addresses a common misconception. Imaginary and complex numbers are indispensable in engineering and physics, not just abstract inventions without real-world application.

Given Data / Assumptions:

• Imaginary unit j (or i in mathematics) satisfies j^2 = −1.
• Complex number z = a + j * b with real part a and imaginary part b.

Concept / Approach:
Imaginary numbers, combined with real numbers to form complex numbers, provide a powerful representation for oscillations, phasors, impedances, control poles/zeros, and quantum amplitudes. Their consequences are measurable and routinely verified in experiments and circuits.

Step-by-Step Solution:

Verification / Alternative check:
Laboratory measurements of phase shifts, resonance peaks, and frequency responses align with complex-number predictions, demonstrating their physical relevance.

Why Other Options Are Wrong:

• Marking “True” denies a century of validated engineering methods that rely on complex numbers to match observed behavior.

Common Pitfalls:
Interpreting “imaginary” as “unreal.” The term is historical; the mathematics maps directly to orthogonal components that correspond to measurable sine and cosine projections.

Final Answer:
False