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Straight Line Questions

Find the equation of line joining the point (3, 5) to the point of intersection of the lines 4x + y – 1 = 0 and 7x – 3y – 35 = 0.

Solution : On solving the equations 4x + y – 1 = 0 and 7x – 3y – 35 = 0 by using point of intersection formula, we get x = 2 and y = -7 So, given lines intersect at (2, -7) Now, the equation of line joining the point (3, 5) and (2, […]

Find the equation of line joining the point (3, 5) to the point of intersection of the lines 4x + y – 1 = 0 and 7x – 3y – 35 = 0. Read More »

Find the coordinates of the point of intersecton of the lines 2x – y + 3 = 0 and x + y – 5 = 0.

Solution : Solving simultaneously the equations 2x – y + 3 = 0 and x + y – 5 = 0, we obtain x53 = y3+10 = 12+1 x2 = y13 = 13 x = 23 , y = \(13\over

Find the coordinates of the point of intersecton of the lines 2x – y + 3 = 0 and x + y – 5 = 0. Read More »

Find the equation of line parallel to y-axis and drawn through the point of intersection of the lines x – 7y + 5 = 0 and 3x + y = 0.

Solution : On solving the equations x – 7y + 5 = 0 and 3x + y = 0 by using point of intersection formula, we get x = 522 and y = 1522 So, given lines intersect at (522.,1522) Let the equation of the required line be x =

Find the equation of line parallel to y-axis and drawn through the point of intersection of the lines x – 7y + 5 = 0 and 3x + y = 0. Read More »

If p is the length of the perpendicular from the origin to the line xa + yb = 1, then prove that 1p2 = 1a2 + 1b2

Solution : The given line is bx + ay – ab = 0 ………….(i) It is given that p = Length of the perpendicular from the origin to line (i) p = |b(0)+a(0)ab|b2+a2 = aba2+b2 p2 = a2b2a2+b2 1p2 = a2+b2a2b2 \(1\over

If p is the length of the perpendicular from the origin to the line xa + yb = 1, then prove that 1p2 = 1a2 + 1b2 Read More »

Find the distance between the line 12x – 5y + 9 = 0 and the point (2,1)

Solution : We have line 12x – 5y + 9 = 0 and the point (2,1) Required distance = |12251+9122+(5)2| = |245+9|13 = 2813 Similar Questions If p is the length of the perpendicular from the origin to the line xa + yb =

Find the distance between the line 12x – 5y + 9 = 0 and the point (2,1) Read More »

If the line 2x + y = k passes through the point which divides the line segment joining the points (1,1) and (2,4) in the ratio 3:2, then k is equal to

Solution : Given line L : 2x + y = k passes through point (Say P) which divides the line segment (let AB) in ration 3:2, where A(1, 1) and B(2, 4). Using section formula, the coordinates of the point P which divides AB internally in the ratio 3:2 are P(\(3\times 2 + 2\times 1\over

If the line 2x + y = k passes through the point which divides the line segment joining the points (1,1) and (2,4) in the ratio 3:2, then k is equal to Read More »

The x-coordinate of the incenter of the triangle that has the coordinates of mid-point of its sides as (0,1), (1,1) and (1,0) is

Solution : Given mid-points of a triangle are (0,1), (1,1) and (1,0). So, by distance formula sides of the triangle are 2, 2 and 22. x-coordinate of the incenter = 20+220+222+2+22 = 22+2 Similar Questions Find the distance between the line 12x – 5y +

The x-coordinate of the incenter of the triangle that has the coordinates of mid-point of its sides as (0,1), (1,1) and (1,0) is Read More »

Let a, b, c and d be non-zero numbers. If the point of intersection of the lines 4ax+2ay+c=0 and 5bx+2by+d=0 lies in the fourth quadrant and is equidistant from the two axes, then

Solution : Since, (α, -α) lie on 4ax+2ay+c=0 and 5bx+2by+d=0. 4aα + 2aα + c = 0 α = c2a  …..(i) Also, 5bα – 2bα + d = 0 α = d3b    …..(i) from equation (i) and (ii), c2a = d3b 3bc = 2ad Similar Questions Find

Let a, b, c and d be non-zero numbers. If the point of intersection of the lines 4ax+2ay+c=0 and 5bx+2by+d=0 lies in the fourth quadrant and is equidistant from the two axes, then Read More »

If PS is the median of the triangle, with vertices of P(2,2), Q(6,-1) and R(7,3), then equation of the line passing through (1,-1) and parallel to PS is

Solution : Since PS is the median, so S is the mid point of triangle PQR. So, Coordinates of S = (7+62,312) = (132, 1) Slope of line PS = (1 – 2)/(13/2 – 2) = 29 Required equation passes through (1, -1) is y + 1 =

If PS is the median of the triangle, with vertices of P(2,2), Q(6,-1) and R(7,3), then equation of the line passing through (1,-1) and parallel to PS is Read More »

If λx210xy+12y2+5x16y3 = 0 represents a pair of straight lines, then λ is equal to

Solution : Comparing with ax2+2hxy+by2+2gx+2fy+c = 0 Here a = λ, b = 12, c = -3, f = -8, g = 5/2, h = -5 Using condition abc+2fghaf2bg2ch2 = 0, we have λ(12)(-3) + 2(-8)(5/2)(-5) – λ(64) – 12(25/4) + 3(25) = 0   -36λ + 200 – 64λ – 75 + 75 =

If λx210xy+12y2+5x16y3 = 0 represents a pair of straight lines, then λ is equal to Read More »