Question

If e^iq = cos q + i sin q, then for the DABC e^iA e^iBe^iC is-

• A. I
• B. 1
• C. –1
• D. None of these

Answer 1

Answer: (C)

–1

Answer 2

Sol. e^iA. e^iB.e^iC = e^i(A+B+C) = e^ip =cos p + i sin p = –1