The equation of the pair of straight lines parallel to x-axis and touching the circle x2 + y2- 6x - 4y -12 = 0 is
y2 - 4y - 21 = 0
y2 + 4y - 21 = 0
y2 - 4y + 21 = 0
y2 + 4y + 21 = 0
A.
y2 - 4y - 21 = 0
Let the lines be y = m1x + c1 and y = m2x + c2.
Since, pair of straight lines are parallel to x-axis
and the lines will be y = c1 and y = c2.
Given circle is x2 + y2 - 6x - 4y - 12 = 0
Centre (3, 2) and radius = 5
Here, the perpendicular drawn from centre to the lines are CP and CP'.
Hence, the lines are
y - 7 = 0, y + 3 = 0 i.e., (y - 7)(0 + 3) = 0
Pair of straight lines is y2 - 4y - 21 = 0
If the lines 3x - 4y - 7 = 0 and 2x - 3y - 5 = 0 are two diameters of a circle of area 49 sq unit, then equation of the circle is
x2 + y2 + 2x - 2y - 62 = 0
x2 + y2 - 2x + 2y - 62 = 0
x2 + y2 - 2x + 2y - 47 = 0
x2 + y2 + 2x - 2y - 47 = 0
The locus of middle point of chords of hyperbola 3x2 - 2y2 + 4x - 6y = 0 parallel to y = 2x is
3x - 4y = 4
3x - 4x + 4 = 0
4x - 3y = 3
3x - 4y = 2