Recent questions tagged complex-number

2 votes
1 answer
3
1 votes
1 answer
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Let $\omega$ denote a complex fifth root of unity. Define $$b_k =\sum_{j=0}^{4} j \omega^{-kj},$$ for $0 \leq k \leq 4$. Then $ \sum_{k=0}^{4} b_k \omega ^k$ is equal to$...
0 votes
1 answer
5
If $\alpha, \beta$ are complex numbers then the maximum value of $\dfrac{\alpha \overline{\beta}+\overline{\alpha}\beta}{\mid \alpha \beta \mid}$ is$2$$1$the expression m...
1 votes
1 answer
7
For the function $(z) = \frac{1}{z^2(e^z-1)}, z=0$ is a pole of order:$1$$2$$3$None of these
0 votes
1 answer
8
How many complex numbers $z$ are there such that $\mid z+1 \mid = \mid z+i \mid$ and $\mid z \mid =5$?$0$$1$$2$$3$
0 votes
1 answer
9
Is the chapter Complex functions part of gate 2019 maths syllabus?Previously questions about analytic functions have been asked a lot. Are they part of the syllabus?
1 votes
1 answer
10
For n ≥ 1, let Gn be the geometric mean of { sin (π/2 . k/n) : 1 ≤ k ≤ n }Then lim n→∞ Gn is
1 votes
3 answers
11
How many complex numbers $z$ are there such that $\mid z+1 \mid = \mid z+i \mid$ and $\mid z \mid = 5$ ?$0$$1$$2$$3$
0 votes
0 answers
12
What is the minimum value of $\mid z+w \mid$ for complex numbers $z$ and $w$ with $zw = 1$?$0$$1$$2$$3$
0 votes
1 answer
13
If $\mid 2^z \mid = 1$ for a non-zero complex number $z$ then which one of the following is necessarily true$Re(z)=0$$\mid z \mid =1$$Re(z) = 1$$\text{No such z exists}$
1 votes
0 answers
14
The real values of $(a+ib)^{\dfrac{1}{n}} + (a-ib)^{\dfrac{1}{n}}$ is
1 votes
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15
The deacy ratio for a system having complex conjugate poles as$(-\dfrac{1}{10} + j\dfrac{2}{15})$ and $(-\dfrac{1}{10} - j\dfrac{2}{15})$ is$7\times10^{-1}$$8\times10^{-2...
0 votes
1 answer
16
Find the modulus and argument of $$\frac{1+i}{7+24i}$$
1 votes
2 answers
17
The value of $\frac{(1-i\sqrt 3)^{30}}{ (1+i)^{60}} \left( i = \sqrt {-1}\right)$ is ______.10-12
2 votes
1 answer
18
For any complex number $z$, $arg$ $z$ defines its phase, chosen to be in the interval $0\leq arg z < 360^{∘}$. If $z_{1}, z_{2}$ and $z_{3}$ are three complex numbers w...
8 votes
4 answers
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0 votes
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