If the sum of the slopes of the lines given by x2 -2cxy -7y2 =0 is four times their product, then c has the value
-1
2
-2
-2
The equation of the straight line passing through the point (4, 3) and making intercepts on the co-ordinate axes whose sum is –1 is
If one of the lines given by 6x2 -xy +4cy2 = 0 is 3x + 4y = 0, then c equals
1
-1
3
3
D.
3
The pair of lines is 6x2-xy +4cy2 =0
On comparing with ax2 +2hxy by2 = 0
we get a = 6, 2h =-1, b= c
therefore
m1 +m2 = -2h/b = 1/4c and m1m2 = a/b = 6/4c
On line of given pair of lines is
3x+4y = 0
slope of line = -3/4 = m1
-3/4 +m2 = 1/4c
m2 = 1/4c + 3/4
1 + 3c = -8 3c = -9
⇒ c = -3
The intercept on the line y = x by the circle x2 +y2 -2x = 0 is AB. Equation of the circle on AB as a diameter is
x2 +y2 -x-y =0
x2 -y2 -x-y =0
x2 +y2 +x-y =0
x2 +y2 +x-y =0
If the tangent at (1, 7) to the curve x2 = y – 6 touches the circle x2 + y2 + 16x + 12y + c = 0 then the value of c is
95
195
185
85
Transforming to parallel axes through a point (p, q), the equation
2x2 + 3xy + 4y2 + x + 18y + 25 = 0 becomes 2x2 + 3xy + 4y2 = 1. Then,
p = - 2, q = 3
p = 2, q = - 3
p = 3, q = - 4
p = - 4, q = 3
The point P(3, 6) is first reflected on the line y =x and then the image point Q is again reflected on the line y = - x to get the image point Q'. Then, the circumcentre of the APQQ' is
(6, 3)
(6,- 3)
(3,- 6)
(0, 0)
Let d1 and d2 be the lengths of the perpendiculars drawn from any point of the line 7x - 9y + 10 = 0 upon the lines 3x + 4y = 5 and 12x +5y = 7, respectively. Then,
d1 > d2
d1 = d2
d1 < d2
d1 = 2d2
The chord of the curve y = x2 + 2ax + b, joining the points where is parallel to the tangent to the curve at abscissa x is equal to
Two particles move in the same straight line starting at the same moment from the same point in the same direction. The first moves with constant velocity u and the second starts from rest with constant acceleration f. Then
they will be at the greatest distance at the end of time from the start
they will be at the greatest distance at the end of time from the start
their greatest distance is
their greatest distance is