Important Questions of Complex Numbers and Quadratic Equations Mathematics | Zigya

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 Multiple Choice QuestionsMultiple Choice Questions

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61.

Consider the following statements in respect of the quadratic equation 4(x p)(x q) r2 = 0, where p, q and r are real numbers:

1) The roots are real

2) The roots are equal if p = q and r = 0

Where of the above statements is/are correct ?

  • 1 only

  • 2 only

  • Both 1 and 2

  • Neither 1 nor 2


62.

How many real roots does the equation x2 + 3|x| + 2 = 0 have ?

  • 1 only

  • 2 Only

  • Both 1 and 2

  • Neither 1 nor 2


63.

Under which one of the following conditions will the quadratic equation x2 + mx + 2 = 0 always have real roots ?

  • 23  m2 < 8

  • 3  m2 < 4

  • m2 8

  • m2  3


64.

If x = 1 + i, then what is the value of x6 + x4 + x2 + 1 ?

  • 6i - 3

  • - 6i + 3

  • - 6i - 3

  • 6i + 3


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65.

If α and β are the roots of x2 + x + 1 = 0, then what is   j = 02α1 + β1 = ?

  • 8

  • 6

  • 4

  • 2


66.

What is the value of i + 322019 + i - 322019 ?

  • 1

  • 2

  • 2i

  • - 2i


67.

If both p and q belong to the set {1, 2, 3, 4}, then how many equations of the form px2 + qx + 1 = 0 will have real roots ?

  • 12

  • 10

  • 7

  • 6


68.

If p and q are the roots of the equation x2 – 30x + 221 = 0, what is the value of p3 + q?

  • 7010

  • 7110

  • 7210

  • 7240


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69.

Let f(x) = x2 + 2x – 5 and g(x) = 5x + 30

Consider the following statements:

1) f[g(x)] is a polynomial of degree 3.

2) g[g(x)] is a polynomial of degree 2.

Which of the above statements is/are correct ?

  • 1 only

  • 2 only

  • Both 1and 2

  • Neither 1 nor 2


70.

What is the argument of the complex number 1 - i31 + i3

where i =  - 1 ?

  • 240°

  • 210°

  • 120°

  • 60°


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