What is the quotient when \(4 + 8i\) is divided by \(i^3\)?
A8-4i
B8+4i
C-8+4i
D-8-4i
#24📜 EE Board October 1997📘 1001 Math RojasEasy
If \(A = -2 - 3i\) and \(B = 3 + 4i\), what is \(\frac{A}{B}\)?
A\(\frac{18-i}{25}\)
B\(\frac{-18-i}{25}\)
C\(\frac{-18+i}{25}\)
D\(\frac{18+i}{25}\)
#25📜 EE Board October 1997📘 1001 Math RojasEasy
Rationalize \(\frac{4+3i}{2-i}\)
A1+2i
B\(\frac{11+10i}{5}\)
C\(\frac{5+2i}{5}\)
D2+2i
#26📜 EE Board April 1996📘 1001 Math RojasEasy
What is the simplified expression of the complex number \(\frac{6+j2.5}{3+j4}\)?
A-0.32 + j0.66
B1.12 - j0.66
C0.32 - j0.66
D1.75 + j1.03
#27📜 EE Board April 1997📘 1001 Math RojasEasy
Perform the operation: \(4(\cos 60^\circ + i \sin 60^\circ)\) divided by \(2(\cos 30^\circ + i \sin 30^\circ)\) in rectangular coordinates.
A\(\sqrt{3} - 2i\)
B\(\sqrt{3} - i\)
C\(\sqrt{3} + i\)
D\(\sqrt{3} + 2i\)
#28📜 EE Board June 1990📘 1001 Math RojasEasy
Find the quotient of \(\frac{50+j35}{8+j5}\)
A\(6.47\angle 3^\circ\)
B\(4.47\angle 3^\circ\)
C\(7.47\angle 30^\circ\)
D\(2.47\angle 53^\circ\)
#29📜 EE Board April 1999📘 1001 Math RojasEasy
Evaluate \(\cosh(j\frac{\pi}{4})\)
A0.707
B1.41 + j0.866
C0.5 + j0.707
Dj0.707
#30📜 EE Board April 1999📘 1001 Math RojasEasy
Evaluate \(\tanh(j\frac{\pi}{3})\)
A0.5 + j1.732
Bj0.866
Cj1.732
D0.5 + j0.866
#31📜 EE Board October 1997📘 1001 Math RojasEasy
Evaluate the terms of a Fourier series \(2 e^{j10\pi t} + 2 e^{-j10\pi t}\) at \(t = 1\)
A2+j
B2
C4
D2+j2
#32📜 EE Board March 1998📘 1001 Math RojasEasy
Given the following series: \(\sin x = x - \frac{x^3}{3!} + \frac{x^5}{5!} - \dots\) \(\cos x = 1 - \frac{x^2}{2!} + \frac{x^4}{4!} - \dots\) \(e^x = 1 + x + \frac{x^2}{2!} + \frac{x^3}{3!} + \dots\) What relation can you draw from these series?
A\(e^x = \cos x + \sin x\)
B\(e^{ix} = \cos x + i \sin x\)
C\(e^{ix} = i \cos x + \sin x\)
D\(i e^x = i \cos x + i \sin x\)
#33📜 EE Board October 1997📘 1001 Math RojasEasy
One term of a Fourier series in cosine form is \(10 \cos 40\pi t\). Write it in exponential form.
If matrix \(\begin{bmatrix} 1 & -1 & 2 \\ 2 & 1 & 3 \\ 0 & -1 & 1 \end{bmatrix}\) is multiplied by \(\begin{bmatrix} x \\ y \\ z \end{bmatrix}\) is equal to zero, then matrix \(\begin{bmatrix} x \\ y \\ z \end{bmatrix}\) is
A3
B1
C0
D-2
#40📜 CE Board November 1997📘 1001 Math RojasEasy
Given the matrix equation, solve for x and y: \(\begin{bmatrix} 1 & 1 \\ 3 & 2 \end{bmatrix} \begin{bmatrix} x \\ y \end{bmatrix} = \begin{bmatrix} 2 \\ 0 \end{bmatrix}\)