Home
Class 12
MATHS
If (x+iy)^(2)-7+24i, then the value of (...

If `(x+iy)^(2)-7+24i`, then the value of `(7+sqrt(-576))^(1//2)-(7-sqrt(-576))^(1//2)`, is

A

`-6i`

B

`-3i`

C

`2i`

D

6

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we will start from the given equation and work through the calculations systematically. ### Step 1: Start with the given equation We are given that: \[ (x + iy)^2 = 7 + 24i \] ### Step 2: Take the square root of both sides Taking the square root of both sides, we have: \[ x + iy = \sqrt{7 + 24i} \] ### Step 3: Find the expression we need to evaluate We need to evaluate the expression: \[ (7 + \sqrt{-576})^{1/2} - (7 - \sqrt{-576})^{1/2} \] ### Step 4: Simplify \(\sqrt{-576}\) We know that \(\sqrt{-576} = \sqrt{576} \cdot \sqrt{-1} = 24i\). Thus, we can rewrite the expression as: \[ (7 + 24i)^{1/2} - (7 - 24i)^{1/2} \] ### Step 5: Use the square root of a complex number Let \(z_1 = 7 + 24i\) and \(z_2 = 7 - 24i\). We can find the square roots of these complex numbers. ### Step 6: Calculate the modulus and argument of \(z_1\) The modulus of \(z_1\) is: \[ |z_1| = \sqrt{7^2 + 24^2} = \sqrt{49 + 576} = \sqrt{625} = 25 \] The argument \(\theta\) can be calculated using: \[ \tan \theta = \frac{24}{7} \] ### Step 7: Find the square root of \(z_1\) The square root of a complex number in polar form is given by: \[ \sqrt{r} \left( \cos\left(\frac{\theta}{2}\right) + i \sin\left(\frac{\theta}{2}\right) \right) \] Thus: \[ \sqrt{7 + 24i} = \sqrt{25} \left( \cos\left(\frac{\theta}{2}\right) + i \sin\left(\frac{\theta}{2}\right) \right) = 5 \left( \cos\left(\frac{\theta}{2}\right) + i \sin\left(\frac{\theta}{2}\right) \right) \] ### Step 8: Find the square root of \(z_2\) Similarly, for \(z_2\): \[ \sqrt{7 - 24i} = \sqrt{25} \left( \cos\left(-\frac{\theta}{2}\right) + i \sin\left(-\frac{\theta}{2}\right) \right) = 5 \left( \cos\left(-\frac{\theta}{2}\right) + i \sin\left(-\frac{\theta}{2}\right) \right) \] ### Step 9: Subtract the two square roots Now we can compute: \[ \sqrt{7 + 24i} - \sqrt{7 - 24i} = 5 \left( \cos\left(\frac{\theta}{2}\right) + i \sin\left(\frac{\theta}{2}\right) \right) - 5 \left( \cos\left(-\frac{\theta}{2}\right) + i \sin\left(-\frac{\theta}{2}\right) \right) \] This simplifies to: \[ 5 \left( 0 + i \left( \sin\left(\frac{\theta}{2}\right) - (-\sin\left(\frac{\theta}{2}\right)) \right) \right) = 10i \sin\left(\frac{\theta}{2}\right) \] ### Step 10: Find the value of \(y\) From the original equation, we had: \[ 2iy = 10i \sin\left(\frac{\theta}{2}\right) \] Thus: \[ y = 5 \sin\left(\frac{\theta}{2}\right) \] ### Step 11: Final value Since we are looking for the imaginary part, we conclude: \[ \text{The value is } 6i \text{ or } -6i \] ### Conclusion The final answer is: \[ -6i \]

To solve the problem step by step, we will start from the given equation and work through the calculations systematically. ### Step 1: Start with the given equation We are given that: \[ (x + iy)^2 = 7 + 24i \] ...
Promotional Banner

Topper's Solved these Questions

  • COMPLEX NUMBERS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section I - Solved Mcqs|141 Videos
  • COMPLEX NUMBERS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section II - Assertion Reason Type|15 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

The value of log_((sqrt(2)-1))(5sqrt(2)-7) is :

If 7sqrt(x)-24=11, what is the value of x?

Write the conjugate of sqrt(-25) (7+ sqrt(-576))

If x = sqrt(7)+(1)/(sqrt(7)) , then the value of (128)^(x^(2)) is-

(sqrt(7)+2sqrt(3))(sqrt(7)-2sqrt(3))

The value of int_(1)^(7sqrt(2)) (1)/(x(2x^(7)+1)dx is

Evaluate the following: (2+sqrt(3))^7+(2-sqrt(3))^7

Simplify: -sqrt((-7)/(4))-sqrt((-1)/(7))

The value of sqrt(7+sqrt(7-sqrt(7+sqrt(7-….)))) upto oo is

If (7+4sqrt(3))^(x^(2-8))+(7-4sqrt(3))^(x^(2-8))=14, then x=

OBJECTIVE RD SHARMA ENGLISH-COMPLEX NUMBERS -Chapter Test
  1. If (x+iy)^(2)-7+24i, then the value of (7+sqrt(-576))^(1//2)-(7-sqrt(-...

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |