If ∝, ß, y are the roots of the equation x3 - 6x2

Subject

Mathematics

Class

JEE Class 12

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

11.

x2 + y2 - 8x + 40 = 05x2 + 5y2 -25x + 80 = 0x2 + y2 - 8x + 16y + 160 = 0From the point P are equal, then P = ?

  • 8, 152

  • - 8, 152

  • 8, - 152

  • - 8, - 152


12.

The equation of the circle concentric with the circle x2 + y2 - 6x + 12y + 15 = 0 and of double its area is

  • x2 + y2 - 6x +12y - 15 = 0

  • x2 + y2 - 6x +12y - 30 = 0

  • x2 + y2 - 6x +12y - 25 = 0

  • x2 + y2 - 6x +12y - 20 = 0


13.

If the circle x2 + y2 + 2x + 3y + 1 = 0 cuts another circle x2 + y+ 4x + 3y + 2 = 0 in A and B, then the equation of the circle with AB as a diameter is

  • x2 + y2  + x + 3y + 1 = 0

  • 2x2 + 2y2  + 2x + 6y + 1 = 0

  • x2 + y2  + x + 6y + 1 = 0

  • 2x2 + 2y2  + x + 3y + 1 = 0


14.

The equation of the hyperbola which passes through the point (2, 3) and has the asymptotes 4x + 3y - 7 = 0 and x - 2y - 1 = 0 is

  • 4x2 + 5xy - 6y2 - 11x + 11y + 50 = 0

  • 4x2 + 5xy - 6y2 - 11x + 11y - 43 = 0

  • 4x2 - 5xy - 6y2 - 11x + 11y + 57 = 0

  • x2 - 5xy - y2 - 11x + 11y - 43 = 0


Advertisement
15.

The product of the perpendicular distances from any point on the hyperbola x2a2 - y2b2 = 1 to its asymtotes is

  • a2b2a2 - b2

  • a2b2a2 + b2

  • a2 + b2a2b2

  • a2 - b2a2b2


16.

If the lines 2x + 3y +12 = 0, x - yy + k = 0 are conjugate with respect to the parabola y2 = 8x, then k is equal to

  • 10

  • 72

  • - 12

  • - 2


17.

Find the equation to the parabola, whose axis parallel to they-axis and which passes through the points (0, 4), (1, 9) and (4, 5) is

  • y = - x+ x + 4

  • y = - x+ x + 1

  • y = - 1912x2 + 7912x + 4

  • y = - 1912x2 + 8912x + 4


Advertisement

18.

If ∝, ß, y are the roots of the equation x3 - 6x2 + 11x - 6 = 0 and if a = ∝2 + ß2 + γ2, b = ∝ß + ßγ + γ∝ and  c = (∝ + ß)(ß + γ)(γ + ∝), then the correct inequality among the following is

  • a < b < c

  • b < a < c

  • b < c < a

  • c < a < b


B.

b < a < c

Given equation x3 - 6x2 + 11x - 6 = 0 has the roots α, β, γ.Given,   a = α2 + β2 + γ2                   . . . i             b = αβ + βγ + γα                 . . . ii              c = α + ββ + γγ + α   . . . iiiIn cubic equation the sum of roots α + β + γ = - - 61 = 6αβ + βγ + γα = 111 = 11product of the rootsαβγ = - - 61 = 6From eq. ii, b = 11From eq i,   a = α2 + β2 + γ2  a = α + β + γ2 - 2 αβ + βγ + γα a = 62 - 211  36 - 22 a = 14From eq iiic = α + ββ + γγ + α    = αβ + β2 + αγ + βγγ + α   = αβγ + β2γ + αγ2 + βγ2 + α2γ + αβγ c = α + β + γ - γα + β + γ - αα + β + γ - β= 6 - γ6 - α6 - β= 36 - 6γ - 6α + αγ6 - β

= 216 - 36γ - 36α + 6αγ - 36β + 6γβ + 6αβ - αβγ= 216 - 6 + 611 - 366=210 + 66 - 216 = 60Hence,                   c = 60b < a < c


Advertisement
Advertisement
19.

A plane meets the coordinate axes at A, B, C so that the centroid of the triangle ABC is (1, 2, 4). Then, the equation of the plane is

  • x + 2y +4z =12

  • 4x + 2y + z = 12

  • x + 2y + 4z = 3

  • 4x + 2y + z = 3


20.

If (2, 3, - 3) is one end of a diameter of the sphere x2 + y+ z- 6x - 12y - 2z + 20 = 0, then the other end of the diameter is

  • (4, 9, - 1)

  • (4, 9, 5)

  • (- 8, - 15, 1)

  • (8, 15, 5)


Advertisement