Home
Class 12
MATHS
If a complex number z lies in the interi...

If a complex number z lies in the interior or on the boundary of a circle or radius 3 and center at `(-4,0)`, then the greatest and least values of `|z+1|` are

A

5,0

B

6,1

C

6,0

D

none of these

Text Solution

AI Generated Solution

The correct Answer is:
To find the greatest and least values of \( |z + 1| \) for a complex number \( z \) that lies within or on the boundary of a circle of radius 3 centered at \((-4, 0)\), we can follow these steps: ### Step 1: Understand the Circle The equation of the circle can be represented as: \[ |z + 4| \leq 3 \] This means that the distance from the point \((-4, 0)\) to the point \( z \) is at most 3. ### Step 2: Rewrite the Expression We want to find the values of \( |z + 1| \). We can rewrite this as: \[ |z + 1| = |(z + 4) - 3| \] This allows us to express \( |z + 1| \) in terms of \( |z + 4| \). ### Step 3: Apply the Triangle Inequality Using the triangle inequality, we have: \[ |z + 1| = |(z + 4) - 3| \geq ||z + 4| - |3| \] This gives us: \[ |z + 1| \geq |z + 4| - 3 \] ### Step 4: Find the Minimum Value Since \( |z + 4| \leq 3 \), we can substitute this into our inequality: \[ |z + 1| \geq |z + 4| - 3 \geq 0 - 3 = -3 \] However, since modulus cannot be negative, we conclude: \[ |z + 1| \geq 0 \] Thus, the least value of \( |z + 1| \) is \( 0 \). ### Step 5: Find the Maximum Value Now, for the maximum value, we can use: \[ |z + 1| \leq |z + 4| + |3| \] Substituting \( |3| = 3 \): \[ |z + 1| \leq |z + 4| + 3 \] Since \( |z + 4| \leq 3 \): \[ |z + 1| \leq 3 + 3 = 6 \] Thus, the greatest value of \( |z + 1| \) is \( 6 \). ### Final Result The least value of \( |z + 1| \) is \( 0 \) and the greatest value is \( 6 \). ### Summary - **Greatest Value**: \( 6 \) - **Least Value**: \( 0 \)
Promotional Banner

Topper's Solved these Questions

  • COMPLEX NUMBERS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|129 Videos
  • CIRCLES

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|53 Videos
  • CONTINUITY AND DIFFERENTIABILITY

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|87 Videos

Similar Questions

Explore conceptually related problems

|z +3| <= 3 , then the greatest and least value of |z | are

If |z+4|lt=3 then find the greatest and least values of |z+1|dot

1. If |z-2+i|≤ 2 then find the greatest and least value of | z|

1. If |z-2+i| ≤ 2 then find the greatest and least value of | z|

If |z-4/z|=2 then the greatest value of |z| is:

If |z-4 +3i| le 2 then the least and the greatest values of |z| are q

Let z be a complex number satisfying 1/2 le |z| le 4 , then sum of greatest and least values of |z+1/z| is :

If z is any complex number such that |z+4|lt=3, then find the greatest value of |z+1|dot

If is any complex number such that |z+4|lt=3, then find the greatest value of |z+1|dot

If |z - 3+ 2i| leq 4 , (where i = sqrt-1 ) then the difference of greatest and least values of |z| is

OBJECTIVE RD SHARMA ENGLISH-COMPLEX NUMBERS -Chapter Test
  1. If z lies on the circle |z-1|=1, then (z-2)/z is

    Text Solution

    |

  2. If a gt 0 and the equation |z-a^(2)|+|z-2a|=3, represents an ellipse, ...

    Text Solution

    |

  3. For any complex number z , find the minimum value of |z|+|z-2i|dot

    Text Solution

    |

  4. Find the greatest and the least value of |z1+z2| ifz1=24+7ia n d|z2|=6...

    Text Solution

    |

  5. about to only mathematics

    Text Solution

    |

  6. If k gt 1, |z(1)| lt k and |(k-z(1)barz(2))/(z(1)-kz(2))|=1, then

    Text Solution

    |

  7. If |z-i|=1 and arg (z) =theta where 0 lt theta lt pi/2, then cottheta-...

    Text Solution

    |

  8. If Re(z)<0 then the value of (1+z+z^2+.....+z^n) cannot exceed

    Text Solution

    |

  9. If z 1 ​ and z 2 ​ are two non zero complex numbers such that ...

    Text Solution

    |

  10. a and b are real numbers between 0 and 1 such that the points Z1 =a+ i...

    Text Solution

    |

  11. If omega is a cube root of unity, then find the value of the following...

    Text Solution

    |

  12. If a ,b ,c and u ,v ,w are the complex numbers representing the vertic...

    Text Solution

    |

  13. If z=re^(itheta) then |e^(iz)| is equal to:

    Text Solution

    |

  14. If a complex number z lies in the interior or on the boundary of a cir...

    Text Solution

    |

  15. Let z1 and z2 be two non - zero complex numbers such that z1/z2+z2/z...

    Text Solution

    |

  16. If z(1),z(2),z(3) be vertices of an equilateral triangle occurig in th...

    Text Solution

    |

  17. Let z be a complex number satisfying |z-5i|<=1 such that amp(z) is min...

    Text Solution

    |

  18. If |z -25i| le 15 then | maximum amp(z) - minimum amp(z)|is equal to

    Text Solution

    |

  19. Let z be a complex number (not lying on x-axis) of maximum modulus suc...

    Text Solution

    |

  20. The maximum distance from the origin of coordinates to the point z sat...

    Text Solution

    |