જો f(z) = z4 - 8z3 + 4z2 + 4z + 39 અને f (3 + 2i) = a + ib તો a:b = .........  from Mathematics સંકર સંખ્યાઓ

Book Store

Download books and chapters from book store.
Currently only available for.
CBSE

Subject

Mathematics
Advertisement
zigya logo

Gujarati JEE Mathematics : સંકર સંખ્યાઓ

Multiple Choice Questions

51. z અને w એ શૂન્યેતર સંકર સંખ્યાઓ છે. જો |zw| = 1 અને argz - argw = bold pi over bold 2 તો bold z with bold bar on top bold space bold w bold space bold equals bold space bold. bold. bold. bold. bold. bold. bold. bold. bold. bold. bold. bold space 
  • -1

  • -i

  • i

  • 1


52. જો સંકર સંખ્યા z  માટે |z - 3 - 2i| ≤ 2, તો |2z - 6 + 5i| નું મહત્વ મૂલ્ય ....... છે. 
  • 14

  • 12

  • 13
  • 11

53.
જો સંકર સંખ્યા bold alpha bold space bold left parenthesis bold space bold alpha bold space bold not equal to bold space bold 1 bold right parenthesis એ સમીકરણ bold z to the power of bold p bold plus bold q end exponent bold space bold minus bold space bold z to the power of bold minus bold space bold minus bold space bold z to the power of bold q bold space bold plus bold space bold 1 bold space bold equals bold space bold 0 જ્યાં p, q ભિન્ન અવિભાજ્ય સંખ્યા છે, નું બીજ હોય તો 
  • 1 + α + α2 + ... + αp = 0
  • 1 + α + α2 + ... + αq = 0 અને 1 + α + a2 + ... + aq-1 = 0
  • 1 + α + a2 + ... αp-1 = 0 અને 1 + α + a2 + ... + aq-1 = 0
  • પરંતુ બંને એક સાથે ન ઉદભવે

Advertisement
54. જો f(z) = z4 - 8z3 + 4z2 + 4z + 39 અને f (3 + 2i) = a + ib તો a:b = ......... 
  • -1 : 8

  • 1 : 8

  • 1 : 4

  • -1 : 4


A.

-1 : 8

Tips: -

ધારો કે z = 3 + 2i
 
bold therefore bold space bold left parenthesis bold z bold minus bold 3 bold right parenthesis to the power of bold 2 bold space bold equals bold space bold 4 bold i to the power of bold 2 bold spaceઆથી z2 - 6z + 13 = 0             ... (1) 

હવે, f(z) ને z2 - 6z + 13 વડે ભાગતાં,

∴ z4 - 8z3 + 4z2 + 4z + 39 = (z2 - 6z + 13) (z2 - 2z + 21) - 96 z + 312 

∴ f(3 + 2i) = 0 (z2 - 2z - 21) - 96 (3 + 2i) - 96 (3 + 2i) + 312 = 24 - 192i = a + ib

∴ a = 24, b = -192

∴ bold a over bold b bold space bold equals bold space bold minus bold 1 over bold 8


Advertisement
Advertisement
55.
bold sin bold space bold italic alpha bold space bold plus bold space bold italic s bold italic i bold italic n bold space bold italic beta bold space bold plus bold space bold italic s bold italic i bold italic n bold space bold italic gamma bold space bold equals bold space bold 0 bold space bold equals bold space bold italic c bold italic o bold italic s bold space bold italic alpha bold space bold plus bold space bold italic c bold italic o bold italic s bold space bold italic beta bold space bold plus bold space bold italic c bold italic o bold italic s bold space bold italic gamma bold spaceજ્યાં bold minus bold space bold pi bold space bold less than bold space bold alpha bold space bold comma bold space bold beta bold comma bold space bold gamma bold space bold less or equal than bold space bold pi
bold જ ો bold space bold sin to the power of bold 2 bold space bold alpha bold space bold plus bold space bold sin to the power of bold 2 bold space bold beta bold space bold plus bold space bold sin to the power of bold n bold space bold gamma bold space bold equals bold space bold 3 over bold 2 bold space bold તથ ા bold space bold sum bold cos bold space bold left parenthesis bold alpha bold space bold plus bold space bold beta bold right parenthesis bold space bold equals bold space bold lambda bold space bold ત ો bold comma bold space bold left parenthesis bold n bold comma bold space bold lambda bold right parenthesis bold space bold equals bold space bold. bold. bold. bold. bold. bold space
  • (2, 3)

  • (0, 3)

  • (2, 0)

  • (2, 3)


56. જો bold alpha bold space bold equals bold space bold cos bold space open parentheses fraction numerator bold 8 bold pi over denominator bold 11 end fraction close parentheses bold space bold plus bold space bold i bold space bold sin bold space open parentheses fraction numerator bold 8 bold pi over denominator bold 11 end fraction close parentheses તો, bold Re bold space bold left parenthesis bold space bold alpha bold space bold plus bold space bold alpha to the power of bold 2 bold space bold plus bold space bold alpha to the power of bold 3 bold space bold plus bold space bold alpha to the power of bold 4 bold space bold plus bold space bold alpha to the power of bold 5 bold right parenthesis bold space bold equals bold space bold. bold. bold. bold. bold. bold. bold space bold.
  • 1

  • 0

  • bold minus bold 1 over bold 2
  • bold 1 over bold 2

57. જો |z| = 1 અને arf (z) = તો arg open parentheses fraction numerator bold 1 bold plus bold z over denominator bold 1 bold plus bold z end fraction close parentheses bold space bold equals bold space bold. bold. bold. bold. bold. bold. bold space bold.
  • θ

  • bold pi bold minus bold theta
  • bold pi over bold 2 bold minus bold theta

58. bold sum from bold k bold equals bold 1 to bold 6 of bold space open parentheses bold sin open parentheses fraction numerator bold 2 bold kπ over denominator bold 7 end fraction close parentheses bold plus bold space bold i bold space bold cos bold space open parentheses fraction numerator bold 2 bold kπ over denominator bold 7 end fraction close parentheses close parentheses bold space bold equals bold space bold. bold. bold. bold. bold. bold. bold space bold.
  • -i
  • 1
  • 0
  • -1

Advertisement
59. જો |z| = 1 અને z ≠ ± 1 તો કોઈ પણ સંકર સંખ્યા z માટે fraction numerator bold z over denominator bold 1 bold space bold minus bold space bold z to the power of bold 2 end fraction  એ = ....... . 
  • Y-અક્ષ પર હોય.

  • ઉંગમબિંદુમાંથી પસાર ન થતી રેખા પર હોય. 
  • X-અક્ષ પર હોય.
  • bold vertical line bold z bold vertical line bold space bold equals bold space square root of bold 2

60. z અને w એ સંકર સંખ્યાઓ છે. જો bold z with bold bar on top bold space bold plus bold space bold i bold space bold w with bold bar on top bold space bold equals bold space bold 0 અને arg (zw) = bold pi તો argz = ............ . 
  • fraction numerator bold 5 bold pi over denominator bold 4 end fraction
  • fraction numerator bold minus bold pi over denominator bold 4 end fraction
  • bold pi over bold 4
  • bold pi over 2

Advertisement

Switch