Maths-
General
Easy
Question
The equation of common tangent to the curves y2 = 8x and xy = –1 is
- 3y = 9x + 2
- y = 2x + 1
- 2y = x + 8
- y = x + 2
The correct answer is: y = x + 2
Any tangent is y = mx + y = mx + . If it is tangent to xy = –1 then it will cut at two coincident points.
x+ 1 = 0 m2x2 + 2x + m = 0
Δ = 0 ; 4 – 4m3 = 0 m = 1 so y = x + 2
Related Questions to study
maths-
Angle between tangents drawn from the point (1, 4) to the parabola y2 = 4x is
Angle between tangents drawn from the point (1, 4) to the parabola y2 = 4x is
maths-General
maths-
The general equation of 2nd degree 9x2 –24xy + 16y2 – 20x –15y – 60 = 0 represents
The general equation of 2nd degree 9x2 –24xy + 16y2 – 20x –15y – 60 = 0 represents
maths-General
maths-
If (2, 0) is the vertex and y-axis is the directrix of the parabola then its focus is
If (2, 0) is the vertex and y-axis is the directrix of the parabola then its focus is
maths-General
maths-
The equation of directrix of the parabola y2 + 4y + 4x + 2 = 0 is
The equation of directrix of the parabola y2 + 4y + 4x + 2 = 0 is
maths-General
maths-
The parametric representation of a parabola is x = 3 + t2, y = 2t – 1. Its focus is -
The parametric representation of a parabola is x = 3 + t2, y = 2t – 1. Its focus is -
maths-General
physics-
A disc of mass 2 M and radius R is placed on a fixed plank (rough) of length L. The coefficient of friction between the plank and disc is = 0.5. String (light) is connected to centre of disc and passing over a smooth light pulley and connected to a block of mass M as shown in the figure. Now the disc is given an angular velocity in clockwise direction and is gently placed on the plank. Consider this instant as t=0. Based on above information, answer the following questions : Mark the correct statement w.r.t. motion of block and disc.
A disc of mass 2 M and radius R is placed on a fixed plank (rough) of length L. The coefficient of friction between the plank and disc is = 0.5. String (light) is connected to centre of disc and passing over a smooth light pulley and connected to a block of mass M as shown in the figure. Now the disc is given an angular velocity in clockwise direction and is gently placed on the plank. Consider this instant as t=0. Based on above information, answer the following questions : Mark the correct statement w.r.t. motion of block and disc.
physics-General
maths-
The locus of the point of intersection of the tangents to the parabola x2 – 4x – 8y + 28 = 0 which are at right angle is -
The locus of the point of intersection of the tangents to the parabola x2 – 4x – 8y + 28 = 0 which are at right angle is -
maths-General
maths-
An equilateral triangle is inscribed in the parabola y2 = 4ax whose vertices are at the parabola, then the length of its side is equal to -
An equilateral triangle is inscribed in the parabola y2 = 4ax whose vertices are at the parabola, then the length of its side is equal to -
maths-General
maths-
If the tangent to the parabola y2 = ax makes an angle of 45º with x-axis, then the point of contact is
If the tangent to the parabola y2 = ax makes an angle of 45º with x-axis, then the point of contact is
maths-General
maths-
Two perpendicular tangents to y2 = 4ax always intersect on the line, if
Two perpendicular tangents to y2 = 4ax always intersect on the line, if
maths-General
maths-
The equation of the tangent to the parabola y2 = 4ax at point (a/t2, 2a/t) is
The equation of the tangent to the parabola y2 = 4ax at point (a/t2, 2a/t) is
maths-General
maths-
The line x + my + n = 0 will touch the parabola y2 = 4ax, if
The line x + my + n = 0 will touch the parabola y2 = 4ax, if
maths-General
maths-
If y1, y2 are the ordinates of two points P and Q on the parabola and y3 is the ordinate of the point of intersection of tangents at P and Q, then
If y1, y2 are the ordinates of two points P and Q on the parabola and y3 is the ordinate of the point of intersection of tangents at P and Q, then
maths-General
maths-
The line y = 2x + c is a tangent to the parabola y2 = 16 x, if c equals
The line y = 2x + c is a tangent to the parabola y2 = 16 x, if c equals
maths-General
maths-
The straight line y = 2x + does not meet the parabola y2 = 2x, if
The straight line y = 2x + does not meet the parabola y2 = 2x, if
maths-General