Home
Class 11
MATHS
Given that (2 sqrt3 cos 30^(@) - 2i sin ...

Given that `(2 sqrt3 cos 30^(@) - 2i sin 30^(@))/(sqrt2 (cos 45^(@) + isin 45^(@)))=A + Bi`, find the values of A and B.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given problem, we will follow these steps: **Step 1: Substitute the trigonometric values.** We know the values of the trigonometric functions: - \( \cos 30^\circ = \frac{\sqrt{3}}{2} \) - \( \sin 30^\circ = \frac{1}{2} \) - \( \cos 45^\circ = \sin 45^\circ = \frac{1}{\sqrt{2}} \) Substituting these values into the expression: \[ \frac{2\sqrt{3} \cos 30^\circ - 2i \sin 30^\circ}{\sqrt{2} (\cos 45^\circ + i \sin 45^\circ)} = \frac{2\sqrt{3} \cdot \frac{\sqrt{3}}{2} - 2i \cdot \frac{1}{2}}{\sqrt{2} \left(\frac{1}{\sqrt{2}} + i \cdot \frac{1}{\sqrt{2}}\right)} \] **Step 2: Simplify the numerator.** Calculating the numerator: \[ 2\sqrt{3} \cdot \frac{\sqrt{3}}{2} = 3 \] \[ -2i \cdot \frac{1}{2} = -i \] Thus, the numerator simplifies to: \[ 3 - i \] **Step 3: Simplify the denominator.** Calculating the denominator: \[ \sqrt{2} \left(\frac{1}{\sqrt{2}} + i \cdot \frac{1}{\sqrt{2}}\right) = \sqrt{2} \cdot \frac{1}{\sqrt{2}} + i \cdot \sqrt{2} \cdot \frac{1}{\sqrt{2}} = 1 + i \] **Step 4: Combine the results.** Now we have: \[ \frac{3 - i}{1 + i} \] **Step 5: Multiply by the conjugate of the denominator.** To simplify this expression, we multiply the numerator and denominator by the conjugate of the denominator: \[ \frac{(3 - i)(1 - i)}{(1 + i)(1 - i)} = \frac{(3 - i)(1 - i)}{1^2 - i^2} = \frac{(3 - i)(1 - i)}{1 - (-1)} = \frac{(3 - i)(1 - i)}{2} \] **Step 6: Expand the numerator.** Expanding the numerator: \[ (3 - i)(1 - i) = 3 \cdot 1 - 3i - i + i^2 = 3 - 3i - i - 1 = 2 - 4i \] So we have: \[ \frac{2 - 4i}{2} = 1 - 2i \] **Step 7: Identify A and B.** From the expression \(1 - 2i\), we can identify: \[ A = 1, \quad B = -2 \] Thus, the values of \(A\) and \(B\) are: \[ \boxed{1} \quad \text{and} \quad \boxed{-2} \] ---
Promotional Banner

Topper's Solved these Questions

  • COMPLEX NUMBERS

    ICSE|Exercise Exercise (F )|28 Videos
  • COMPLEX NUMBER

    ICSE|Exercise MULTIPLE CHOICE QUESTIONS |34 Videos
  • COMPOUND AND MULTIPLE ANGLES

    ICSE|Exercise CHEPTER TEST |23 Videos

Similar Questions

Explore conceptually related problems

The value of (4(cos75^(@) + isin 75^(@)))/(0.4(cos30^(@) + i sin 30^(@))) is :

If 2 cos (A-B) = 2 sin ( A+ B) = sqrt3 find the value of acute angles A and B .

Prove that cos 30 ^(@) = (sqrt3)/(2)

Evaluate : 14 sin 30^(@)+6cos 60^(@)-5tan 45^(@)

Evaluate : 14 sin 30^(@)+6cos 60^(@)-5tan 45^(@)

If cos^(2)30^(@)+cos^(2)45^(@)+cos^(2)60^(@)=x , then find the value of 'x'

Show that : sin 30^(@)=sqrt((1-cos60^(@))/(2))

If A-B=30^(@)andsinA=(sqrt(3))/(2) ,then find the value of B.

Evaluate (2tan45^@ xx cos 60^@)/sin30^@

cos (A +B) + sin (A -B) = 2 sin (45 ^(@) + A) cos ( 45 ^(@) + B).

ICSE-COMPLEX NUMBERS-Chapter Test
  1. If z(1), z(2) in C (set of complex numbers), prove that |z(1) + z(2)| ...

    Text Solution

    |

  2. If z = x + yi, omega = (2-iz)/(2z-i) and |omega|=1, find the locus of ...

    Text Solution

    |

  3. Simplify: (1- 3omega + omega^(2)) (1 + omega- 3omega^(2))

    Text Solution

    |

  4. Find the locus of z satisfying |(z-3)/(z+1)|=3 in the complex plane.

    Text Solution

    |

  5. Given that (2 sqrt3 cos 30^(@) - 2i sin 30^(@))/(sqrt2 (cos 45^(@) + i...

    Text Solution

    |

  6. Simplify : (1- omega) (1- omega^(2)) (1- omega^(4)) (1- omega^(8))

    Text Solution

    |

  7. Find the locus of a complex number z= x + yi, satisfying the relation ...

    Text Solution

    |

  8. Find the real values of x and y satisfying the equality (x-2 + (y-3)i)...

    Text Solution

    |

  9. If i= (sqrt-1), prove that following (x+1+i) (x+ 1-i) (x-1-i) (x-1+ i)...

    Text Solution

    |

  10. If z= x + yi and |2z + 1| = |z- 2i|, show that 3(x^(2) + y^(2)) + 4(x-...

    Text Solution

    |

  11. Find the amplitude of the complex number "sin" (6pi)/(5) + i (1- "cos"...

    Text Solution

    |

  12. Express (1- 2i)/(2+i) + (3+i)/(2-i) in the form a + bi

    Text Solution

    |

  13. Find the value of x and y given that (x + yi) (2-3i)=4+i

    Text Solution

    |

  14. If the ratio (z-i)/(z-1) is purely imaginary, prove that the point z l...

    Text Solution

    |

  15. If (-2 + sqrt-3) (-3 + 2 sqrt-3) = a + bi, find the real numbers a and...

    Text Solution

    |

  16. If 1, omega, omega^(2) are the three cube roots of unity, then simplif...

    Text Solution

    |

  17. Find the locus of a complex number z= x+yi, satisfying the relation |3...

    Text Solution

    |

  18. Find the modulus and argument of the complex number (2 + i)/(4i + (1+ ...

    Text Solution

    |

  19. If |z-3+ i|=4, then the locus of z is

    Text Solution

    |

  20. The locus of the point z is the Argand plane for which |z +1|^(2) + |z...

    Text Solution

    |