MCQOPTIONS
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This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Complex Analysis knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Let f(z)=z4+a1z3+a2z2+a3z+a4=0; a1, a2, a3, a4 being real and non-zero. If f has a purely imaginary root, then what is the value of the expression a3/(a1a2)+ a1a4/(a2a3) ? |
| A. | 0 |
| B. | 1 |
| C. | -2 |
| D. | 2 |
| Answer» C. -2 | |
| 2. |
For a∈R, let f(z)=z5-5z+a. Select the correct statement for α satisfying f(α)=0. |
| A. | α has exactly three possible real values for a>4 |
| B. | α has exactly one possible real value for a>4 |
| C. | α has exactly three possible real values for a<-4 |
| D. | α has exactly one possible real value for -4<a<4 |
| Answer» C. α has exactly three possible real values for a<-4 | |
| 3. |
Let f(z)=|1–z|, if zk=cos(2kπ/10)+isin(2kπ/10), then find the value of f(z1)×f(z2)×…×f(z9). |
| A. | 10 |
| B. | 15 |
| C. | 20 |
| D. | 30 |
| Answer» B. 15 | |
| 4. |
Consider a function f(z) of degree two, having real coefficients. If z1 and z2 satisfying f(z1)=f(z2)=0 are such that Re z1=Re z2=0 and if z3 satisfies f(f(z3))=0, then select the correct statement. |
| A. | Re z3=0 |
| B. | Im z3=0 |
| C. | Re z3×Imz3≠0 |
| D. | Re z3=0 and Im z3=0 |
| Answer» D. Re z3=0 and Im z3=0 | |
| 5. |
Let f(z)=|z|2+Re z(2(z+z̅)+3(z-z̅)/2i, the find the maximum value of |z|2/f(z). |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 6. |
Find the range of the function defined by f(z)=Re[2iz/(1-z2)]. |
| A. | (−∞, 0) ⋃ (0, ∞) |
| B. | [2, ∞) |
| C. | (−∞, −1] ⋃ [1, ∞) |
| D. | (−∞, 0] ⋃ [2, ∞) |
| Answer» D. (−∞, 0] ⋃ [2, ∞) | |
| 7. |
Let f(z)=2(z+z̅)+3i(z-z̅) and g(z)=|z|. f(z)=2 divides the region g(z)≤6 into two parts. If Q={(2+3i/4), (5/2+3i/4), (1/4-i/4), (1/8+i/4)}, then find the number of elements of Q lying inside the smaller part. |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 8. |
Define f(z)=z2+bz−1=0 and g(z)=z2+z+b=0. If there exists α satisfying f(α)=g(α)=0, which of the following cannot be a value of b? |
| A. | √3i |
| B. | -√3i |
| C. | 0 |
| D. | √3i/2 |
| Answer» E. | |
| 9. |
Let f(z)=arg 1/(1 – z), then find the range of f(z) for |z|=1, z≠1. |
| A. | (-∞, π/2) |
| B. | (-π/2, π/2) |
| C. | (-∞, ∞) |
| D. | [0, π/2) |
| Answer» C. (-∞, ∞) | |
| 10. |
Let x, y, z be integers, not all simultaneously equal. If ω is a cube root of unity with Im(ω)≠1, and if f(z)=az2+bz+c, then find the range of |f(ω)|. |
| A. | (0, ∞) |
| B. | [1, ∞) |
| C. | (√3/2, ∞) |
| D. | [1/2, ∞) |
| Answer» C. (√3/2, ∞) | |
| 11. |
For all complex numbers z satisfying Im(z)≠0, if f(z)=z2+z+1 is a real valued function, then find its range. |
| A. | (-∞, -1] |
| B. | (-∞, 1/3) |
| C. | (-∞, 1/2] |
| D. | (-∞, 3/4) |
| Answer» E. | |
| 12. |
Let f(z)=(z2–z–1)7. If α2+α+1=0 and Im(α)>0, then find f(α). |
| A. | 128α |
| B. | -128α |
| C. | 128α2 |
| D. | -128α2 |
| Answer» D. -128α2 | |
| 13. |
For the function f(z)=zi, what is the value of |f(ω)|+Arg f(ω), ω being the cube root of unity with Im(ω)>0? |
| A. | e-2π/3 |
| B. | e2π/3 |
| C. | e-2π/3+2π/3 |
| D. | e-2π/3-2π/3 |
| Answer» B. e2π/3 | |
| 14. |
Let f(z)=z+1/z. What will be the definition of this function in polar form? |
| A. | (r+1/r)cosθ+i(r-1/r)sinθ |
| B. | (r-1/r)cosθ+i(r+1/r)sinθ |
| C. | (r+1/r)sinθ+i(r-1/r)cosθ |
| D. | (r+1/r)sinθ+i(r-1/r)cosθ |
| Answer» B. (r-1/r)cosθ+i(r+1/r)sinθ | |
| 15. |
Find the domain of the function defined by f(z)=z/(z+z̅). |
| A. | Im(z)≠0 |
| B. | Re(z)≠0 |
| C. | Im(z)=0 |
| D. | Re(z)=0 |
| Answer» C. Im(z)=0 | |