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if |z|=3 then the points representing th...

if `|z|=3` then the points representing thecomplex numbers `-1+4z` lie on a

A

line

B

circle

C

parabola

D

none of these

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The correct Answer is:
To solve the problem, we need to determine the geometric representation of the complex numbers of the form \(-1 + 4z\) given that \(|z| = 3\). ### Step-by-Step Solution: 1. **Understanding the Given Information**: We know that \(|z| = 3\). This means that the complex number \(z\) lies on a circle of radius 3 centered at the origin in the complex plane. 2. **Expressing the Complex Number**: We need to analyze the expression \(-1 + 4z\). Let's denote this complex number as \(a\): \[ a = -1 + 4z \] 3. **Finding the Modulus**: We can find the modulus of \(4z\): \[ |4z| = 4|z| = 4 \times 3 = 12 \] Thus, the modulus of \(4z\) is 12. 4. **Relating the Modulus to \(a\)**: We can express the modulus of \(a\): \[ |a + 1| = |4z| \] This means: \[ |a + 1| = 12 \] 5. **Setting Up the Equation**: Let \(a = x + iy\) where \(x\) and \(y\) are real numbers. Then: \[ |(x + 1) + iy| = 12 \] This can be rewritten as: \[ \sqrt{(x + 1)^2 + y^2} = 12 \] 6. **Squaring Both Sides**: Squaring both sides gives: \[ (x + 1)^2 + y^2 = 144 \] 7. **Identifying the Geometric Shape**: The equation \((x + 1)^2 + y^2 = 144\) represents a circle in the complex plane. The center of this circle is at \((-1, 0)\) and the radius is \(12\). ### Conclusion: The points representing the complex numbers \(-1 + 4z\) lie on a circle with center at \((-1, 0)\) and radius \(12\).

To solve the problem, we need to determine the geometric representation of the complex numbers of the form \(-1 + 4z\) given that \(|z| = 3\). ### Step-by-Step Solution: 1. **Understanding the Given Information**: We know that \(|z| = 3\). This means that the complex number \(z\) lies on a circle of radius 3 centered at the origin in the complex plane. 2. **Expressing the Complex Number**: ...
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OBJECTIVE RD SHARMA ENGLISH-COMPLEX NUMBERS -Chapter Test
  1. if |z|=3 then the points representing thecomplex numbers -1+4z lie on ...

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  2. The locus of the center of a circle which touches the circles |z-z1|=a...

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  3. Prove that for positive integers n(1) and n(2), the value of express...

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  4. The value of abs(sqrt( 2i) - sqrt(2i)) is :

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  5. Prove that the triangle formed by the points 1,(1+i)/(sqrt(2)),a n di ...

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  6. The value of ((1+ i sqrt(3))/(1-isqrt(3)))+ ((1-isqrt(3))/(1+isqrt(3)...

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  7. If alpha+ibeta=tan^(-1) (z), z=x+iy and alpha is constant, the locus o...

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  8. If cosA+cosB+cosC=0,sinA+sinB+sinC=0andA+B+C=180^(@) then the value of...

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  9. Find the sum 1xx(2-omega)xx(2-omega^(2))+2xx(-3-omega)xx(3-omega^(2))+...

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  10. The value of the expression (1+(1)/(omega))+(1+(1)/(omega^(2)))+(2+(1)...

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  11. The condition that x^(n+1)-x^(n)+1 shall be divisible by x^(2)-x+1 is ...

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  12. The expression (1+i)^(n1)+(1+i^(3))^(n2) is real iff

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  13. If |{:(6i,3i,1),(4,3i,-1),(20,3,i):}|=x+iy, then (x, y) is equal to

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  14. If cosalpha+2cosbeta+3cosgamma=sinalpha+2sinbeta+3singamma=0,t h e nt ...

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  15. If cosalpha+2cosbeta+3cosgamma=sinalpha+2sinbeta+3singamma=0,t h e nt ...

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  16. Sum of the series sum(r=0)^n (-1)^r ^nCr[i^(5r)+i^(6r)+i^(7r)+i^(8r)] ...

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  17. If az(1)+bz(2)+cz(3)=0 for complex numbers z(1),z(2),z(3) and real num...

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  18. If 2z1-3z2 + z3=0, then z1, z2 and z3 are represented by

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  19. If Re((z+4)/(2z-1)) = 1/2 then z is represented by a point lying on

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  20. The vertices of a square are z(1),z(2),z(3) and z(4) taken in the anti...

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  21. Let lambda in R . If the origin and the non-real roots of 2z^2+2z+lam...

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