Questions
Question 1
*
State the definition of \(e^{x+iy}\) for real \(x\) and \(y\).
Question 2
*
What is the period of the complex exponential in the imaginary direction?
Question 3
*+
Evaluate \(e^{i\pi/2}\).
Question 4
*+
Evaluate \(e^{2+i0}\).
Question 5
**
Write \(e^{1+i\pi}\) in Cartesian form.
Question 6
**
Find the modulus of \(e^{3-2i}\).
Question 7
**+
Find the principal argument of \(e^{-1+i5\pi/6}\).
Question 8
**+
Simplify \(e^{2+i\pi/3}e^{-1+i\pi/6}\).
Question 9
***
Solve \(e^z=1\) for complex \(z\).
Question 10
***
Solve \(e^z=-1\) for complex \(z\).
Question 11
***+
Explain why \(e^{z_1+z_2}=e^{z_1}e^{z_2}\) is consistent with rotation and scaling.
Question 12
***+
A student says \(e^{i\theta}\) grows as \(\theta\) grows because exponentials grow. Correct the statement.
Question 13
****
Find all \(z\) such that \(e^z=2i\).
Question 14
****
Find all \(z\) such that \(e^{2z}=1\).
Question 15
****+
For which real \(t\) is \(|e^{t+i\pi/4}|=5\)?
Question 16
****+
For which real \(t\) is \(e^{1+it}\) purely imaginary and above the origin?
Question 17
****+
For which real \(t\) does \(e^{t+i t}\) lie on the unit circle?
Question 18
*****
Prove that \(e^{z+2\pi i}=e^z\) for every complex \(z\).
Question 19
*****
Show that \(e^z\ne0\) for every complex \(z\).
Question 20
*****
Explain why the equation \(e^z=w\) has infinitely many solutions for every non-zero complex number \(w\).