17 Chapter in Review Answers to selected odd-numbered problems begin on page ANS-46.
Answer Problems 1–16 without referring back to the text. Fill in the blank or answer true/false.
- Re(1 + i)10 = _____ and Im(1 + i)10 = _____.
- If z is a point in the third quadrant, then i is in the _____ quadrant.
- If z = 3 + 4i, then Re = _____.
- i127 − 5i9 + 2i−1 = _____
- If z = , then |z| = _____.
- Describe the region defined by 1 ≤ |z + 2| ≤ 3. _____
- Arg(z + ) = 0 _____
- If z = , then Arg z = _____.
- If ez = 2i, then z = _____.
- If |ez| = 1, then z is a pure imaginary number. _____
- The principal value of (1 + i)(2+i) is _____.
- If f(z) = x2 − 3xy − 5y3 + i(4x2y − 4x + 7y), then f(−1 + 2i) = _____.
- If the Cauchy–Riemann equations are satisfied at a point, then the function is necessarily analytic there. _____
- f(z) = ez is periodic with period _____.
- Ln(−ie3) = _____
- f(z) = sin(x − iy) is nowhere analytic. _____
In Problems 17–20, write the given number in the form a + ib.
- i(2 − 3i)2(4 + 2i)
- 4eπi/3e−πi/4
In Problems 21–24, sketch the set of points in the complex plane satisfying the given inequality.
- Im(z2) ≤ 2
- Im(z + 5i) > 3
- ≤ 1
- Im(z) < Re(z)
- Look up the definitions of conic sections in a calculus text. Now describe the set of points in the complex plane that satisfy the equation |z − 2i| + |z + 2i| = 5.
- Let z and w be complex numbers such that |z| = 1 and |w| ≠ 1. Prove that
In Problems 27 and 28, find all solutions of the given equation.
- z4 = 1 − i
- If f(z) = z24 − 3z20 + 4z12 − 5z6, find .
- Write f(z) = Im(z − 3) + zRe(z2) − 5z in the form f(z) = u(x, y) + iv(x, y).
In Problems 31 and 32, find the image of the line x = 1 in the w-plane under the given mapping.
- f(z) = x2 − y + i(y2 − x)
- f(z) =
In Problems 33–36, find all complex numbers for which the given statement is true.
- z = z−1
- = −z
- z2 = ()2
- Show that the function f(z) = −(2xy + 5x) + i(x2 − 5y − y2) is analytic for all z. Find f′(z).
- Determine whether the function
f(z) = x3 + xy2 − 4x + i(4y − y3 − x2y)
is differentiable. Is it analytic?
In Problems 39 and 40, verify the given equality.
- Ln[(1 + i)(1 − i)] = Ln(1 + i) + Ln(1 − i)
- = Ln(1 + i) − Ln(1 − i)