Home
Class 11
MATHS
If k x^2 + 10 xy + 3 y^2 - 15x - 21y + 1...

If `k x^2 + 10 xy + 3 y^2 - 15x - 21y + 18 = 0` represents a pair of straight lines. Then the value of `k` is :

A

-3

B

3

C

4

D

-4

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • BINOMIAL THEOREM AND PRINCIPLE OF MATHEMATICAL INDUCTION

    PATHFINDER|Exercise QUESTION BANK|68 Videos
  • CIRCLE

    PATHFINDER|Exercise QUESTION BANK|198 Videos

Similar Questions

Explore conceptually related problems

If x^2-3xy+lambda y^2+3x-5y+2=0 ,represent a pair of straight lines, then the value of lambda is

If lambdax^(2)-10xy+12y^(2)+5x-16y-3=0 , represents a pair of straight lines, then the value of lambda is

If the equation 2x^(2)+2hxy +6y^(2) - 4x +5y -6 = 0 represents a pair of straight lines, then the length of intercept on the x-axis cut by the lines is equal to

The equation of second degree x^2 + 2sqrt2 xy + 2y^2 + 4x + 4 sqrt2 y + 1 = 0 represents a pair of straight lines, the distance between them is :

The value of lambda with |lambda| lt 16 such that 2x^(2) - 10xy +12y^(2) +5x +lambda y - 3 = 0 represents a pair of straight lines is

If the equation 2x^2+k x y+2y^2=0 represents a pair of real and distinct lines, then find the values of kdot

The equation x^2y^2-9y^2-6x^2y+54 y=0 represents (a) a pair of straight lines and a circle (b) a pair of straight lines and a parabola (c) a set of four straight lines forming a square (d) none of these

x^2-x y+y^2-4x-4y+16=0 represents a. a point b. a circle c. a pair of straight line d. none of these

The equation x^2-3xy+lambda y^2+3x-5y+2=0 where lambda is a real number, represents a pair of straight lines If theta is the angle between the line , then frac(cosec^2theta)(2) is

The equation 3x^2+4y^2-18x+16 y+43=k represents an empty set, if k 0 represents a point, if k=0 cannot represent a real pair of straight lines for any value of k

PATHFINDER-CARTESIAN COORDINATES AND STRAIGHT LINE-QUESTION BANK
  1. The co-ordinates of a point on the line y = x where perpendicular dist...

    Text Solution

    |

  2. If the points (1,2) and (3, 4) are on the opposite side of the line 3x...

    Text Solution

    |

  3. If k x^2 + 10 xy + 3 y^2 - 15x - 21y + 18 = 0 represents a pair of str...

    Text Solution

    |

  4. The point of intersection of the straight lines given by the equation ...

    Text Solution

    |

  5. If the equation 12x^2 + 7xy - py^2 - 18x qy + 6 = 0 represent two perp...

    Text Solution

    |

  6. If the angle between the two lines represented by 2x^2 + 5xy + 3y^2 + ...

    Text Solution

    |

  7. The equation of second degree x^2 + 2sqrt2 xy + 2y^2 + 4x + 4 sqrt2 y ...

    Text Solution

    |

  8. The point (4,1) undergoes the following transformation successively (i...

    Text Solution

    |

  9. Mixed term xy is to be removed from the general equation of second deg...

    Text Solution

    |

  10. For points P=(x1,y1)and Q =(x2,y2) of the co-ordinate plane a new dist...

    Text Solution

    |

  11. The orthocentre of the triangle formed by the lines x+y=1,2x+3y=6and 4...

    Text Solution

    |

  12. A straight line L with negative slope passes through the point (8,2) a...

    Text Solution

    |

  13. The distance between the circumcentre and orthocentre of the triangle ...

    Text Solution

    |

  14. If P(1+alpha/sqrt2 ,2+ alpha/sqrt2) be any point on a line, then the r...

    Text Solution

    |

  15. If the point (a,a) fall between the lines |x+y|=2,then

    Text Solution

    |

  16. Two fixed point A and B are taken on the cordinate axes such that OA =...

    Text Solution

    |

  17. A variable line through the point of intersection of the lines x/a+y/b...

    Text Solution

    |

  18. The equations of the line passing through the point of intersection o...

    Text Solution

    |

  19. A ray of light travelling along the line 2x-3y+5=0 ,after striking a p...

    Text Solution

    |

  20. Line L has intercepts a and b on the coordinate axes. When the axes ar...

    Text Solution

    |