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Find the conjugate of each of the follow...

Find the conjugate of each of the following :
`{:((i),(-5-2i),(ii),(1)/((4+3i)),(iii),((1+i)^(2))/((3-i)),(iv),((1+i)(2+i))/((3+i))),((v),sqrt(-3),(vi),sqrt(2),(vii),-sqrt(-1),(viii),(2-5i)^(2)):}`

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To find the conjugate of each of the given complex numbers, we will follow the definition of the conjugate of a complex number. The conjugate of a complex number \( z = x + iy \) is given by \( \overline{z} = x - iy \). Let’s solve each part step by step. ### Step 1: Find the conjugate of \( i \) - Given: \( z = i \) - Here, \( x = 0 \) and \( y = 1 \). - Conjugate: \( \overline{z} = 0 - 1i = -i \) ### Step 2: Find the conjugate of \( -5 - 2i \) - Given: \( z = -5 - 2i \) - Here, \( x = -5 \) and \( y = -2 \). - Conjugate: \( \overline{z} = -5 + 2i \) ### Step 3: Find the conjugate of \( \frac{1}{4 + 3i} \) - Given: \( z = \frac{1}{4 + 3i} \) - To eliminate \( i \) from the denominator, multiply by the conjugate of the denominator: \[ \overline{4 + 3i} = 4 - 3i \] - Thus, \[ z = \frac{1 \cdot (4 - 3i)}{(4 + 3i)(4 - 3i)} = \frac{4 - 3i}{16 + 9} = \frac{4 - 3i}{25} \] - Conjugate: \( \overline{z} = \frac{4}{25} + \frac{3}{25}i \) ### Step 4: Find the conjugate of \( \frac{(1+i)^2}{3-i} \) - First, calculate \( (1+i)^2 \): \[ (1+i)^2 = 1^2 + 2(1)(i) + i^2 = 1 + 2i - 1 = 2i \] - Now, \( z = \frac{2i}{3-i} \). - Multiply by the conjugate of the denominator: \[ \overline{3-i} = 3 + i \] - Thus, \[ z = \frac{2i(3+i)}{(3-i)(3+i)} = \frac{6i + 2i^2}{9 + 1} = \frac{6i - 2}{10} = \frac{-2}{10} + \frac{6}{10}i = -\frac{1}{5} + \frac{3}{5}i \] - Conjugate: \( \overline{z} = -\frac{1}{5} - \frac{3}{5}i \) ### Step 5: Find the conjugate of \( \frac{(1+i)(2+i)}{3+i} \) - First, calculate \( (1+i)(2+i) \): \[ (1+i)(2+i) = 2 + i + 2i + i^2 = 2 + 3i - 1 = 1 + 3i \] - Now, \( z = \frac{1 + 3i}{3+i} \). - Multiply by the conjugate of the denominator: \[ \overline{3+i} = 3 - i \] - Thus, \[ z = \frac{(1 + 3i)(3 - i)}{(3+i)(3-i)} = \frac{3 - i + 9i - 3i^2}{9 + 1} = \frac{3 - i + 9i + 3}{10} = \frac{6 + 8i}{10} = \frac{3}{5} + \frac{4}{5}i \] - Conjugate: \( \overline{z} = \frac{3}{5} - \frac{4}{5}i \) ### Step 6: Find the conjugate of \( \sqrt{-3} \) - Given: \( z = \sqrt{-3} = i\sqrt{3} \) - Conjugate: \( \overline{z} = -i\sqrt{3} \) ### Step 7: Find the conjugate of \( \sqrt{2} \) - Given: \( z = \sqrt{2} \) - Conjugate: \( \overline{z} = \sqrt{2} \) ### Step 8: Find the conjugate of \( -\sqrt{-1} \) - Given: \( z = -\sqrt{-1} = -i \) - Conjugate: \( \overline{z} = i \) ### Step 9: Find the conjugate of \( (2-5i)^2 \) - Calculate \( (2-5i)^2 \): \[ (2-5i)^2 = 4 - 20i + 25i^2 = 4 - 20i - 25 = -21 - 20i \] - Conjugate: \( \overline{z} = -21 + 20i \) ### Summary of Conjugates: 1. \( i \) → \( -i \) 2. \( -5 - 2i \) → \( -5 + 2i \) 3. \( \frac{1}{4 + 3i} \) → \( \frac{4}{25} + \frac{3}{25}i \) 4. \( \frac{(1+i)^2}{3-i} \) → \( -\frac{1}{5} - \frac{3}{5}i \) 5. \( \frac{(1+i)(2+i)}{3+i} \) → \( \frac{3}{5} - \frac{4}{5}i \) 6. \( \sqrt{-3} \) → \( -i\sqrt{3} \) 7. \( \sqrt{2} \) → \( \sqrt{2} \) 8. \( -\sqrt{-1} \) → \( i \) 9. \( (2-5i)^2 \) → \( -21 + 20i \)
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RS AGGARWAL-COMPLEX NUMBERS AND QUADRATIC EQUATIONS-EXERCISE 5 B
  1. If |z + i| = |z - i|, prove that z is real.

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  2. Give an example of two complex numbers z(1) and z(2) such that z(1) ne...

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  3. Find the conjugate of each of the following : {:((i),(-5-2i),(ii),(1...

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  4. Find the modulus of each of the following : {:((i),(3+sqrt(-5)),(ii)...

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  5. Find the multiplicative inverse of each of the following : (i)" "(1-...

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  6. If ((1-i)/(1+i))^(100)=a+i b ,\ fin d\ (a , b)

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  7. If ((1+i)/(1-i))^3-((1-i)/(1+i))^3=x+i y ,\ fin d\ (x , y)

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  8. If x + i y =(a+i b)/(a-i b),prove that x^2+y^2=1.

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  9. If a+i b=(c+i)/(c-i) , where c is real, prove that:a^2+b^2=1a n d b/a=...

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  10. Show that (1-i)^(n)(1-(1)/(i))^(n)=2^(n) for all n in N

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  11. What is the smallest positive integer n for which (1+i)^(2n)=(1-i)^(2n...

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  12. Prove that: x^4=4=(x+1+i)(x+1-i)(x-1+i(x-1-i)dot)

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  13. if a = costheta +i sin theta , prove that (1+a)/(1-a) = cot(theta/2)i

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  14. If z1=2-i ,\ z2=1+i , find |(z1+z2+1)/(z1-z2+i)|

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  15. Find the real values of x and y for which : {:((i),(1-i)x+(1+i)y=1 -...

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  16. Find the real numbers x\ a n d\ y , if (x-i y)(3+5i) is the conjugate ...

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  17. Find real values of xa n dy for which the complex numbers -3+i x^2ya n...

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  18. If z=2-3i show that z^2=4z+13=0 and hence find the value of 4z^3-3z^2+...

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  19. if (1+i)z=(1-i)barz then z is

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  20. If ((z-1)/(z+1)) is purely an imaginary number and z ne -1 then find t...

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