मराठी

Find the equation of the straight line which passes through the point (−3, 8) and cuts off positive intercepts on the coordinate axes whose sum is 7.

Advertisements
Advertisements

प्रश्न

Find the equation of the straight line which passes through the point (−3, 8) and cuts off positive intercepts on the coordinate axes whose sum is 7.

थोडक्यात उत्तर
Advertisements

उत्तर

The equation of the line with intercepts a and b is \[\frac{x}{a} + \frac{y}{b} = 1\]. 

Here, a + b = 7   

\[\Rightarrow\] b = 7 − a             ... (1)
The line passes through (−3, 8).

∴ \[\frac{- 3}{a} + \frac{8}{b} = 1\]      ... (2)

Substituting b = 7 − a in (2) we get,

\[\frac{- 3}{a} + \frac{8}{7 - a} = 1\]

\[ \Rightarrow - 3\left( 7 - a \right) + 8a = 7a - a^2 \]

\[ \Rightarrow a^2 + 4a - 21 = 0\]

\[ \Rightarrow \left( a - 3 \right)\left( a + 7 \right) = 0\]

\[ \Rightarrow a = 3, a \neq - 7 \left( \because \text { a is positive } \right)\]

Substituting a = 3 in (1) we get,
b = 7 − 3 = 4
Hence, the equation of the line is \[\frac{x}{3} + \frac{y}{4} = 1\]  or 4x + 3y = 12

shaalaa.com
Equations of Line in Different Forms - Equation of Family of Lines Passing Through the Point of Intersection of Two Lines
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 23: The straight lines - Exercise 23.6 [पृष्ठ ४७]

APPEARS IN

आर.डी. शर्मा Mathematics [English] Class 11
पाठ 23 The straight lines
Exercise 23.6 | Q 10 | पृष्ठ ४७

संबंधित प्रश्‍न

Draw the lines x = − 3, x = 2, y = − 2, y = 3 and write the coordinates of the vertices of the square so formed.


Find the equation of a line equidistant from the lines y = 10 and y = − 2.


Find the equation of the straight line passing through the point (6, 2) and having slope − 3.


Find the equation of the straight line passing through (−2, 3) and inclined at an angle of 45° with the x-axis.


Find the equations to the altitudes of the triangle whose angular points are A (2, −2), B (1, 1) and C (−1, 0).


Find the equation of the straight lines passing through the following pair of point :

(0, −a) and (b, 0)


Find the equation of the straight lines passing through the following pair of point :

(a, b) and (a + b, a − b)


Find the equation of the straight lines passing through the following pair of point :

(a cos α, a sin α) and (a cos β, a sin β)


Find the equations of the medians of a triangle, the coordinates of whose vertices are (−1, 6), (−3, −9) and (5, −8).


Find the equations to the diagonals of the rectangle the equations of whose sides are x = a, x = a', y= b and y = b'.


The vertices of a quadrilateral are A (−2, 6), B (1, 2), C (10, 4), and D (7, 8). Find the equation of its diagonals.


The length L (in centimeters) of a copper rod is a linear function of its celsius temperature C. In an experiment, if L = 124.942 when C = 20 and L = 125.134 when C = 110, express L in terms of C.


The owner of a milk store finds that he can sell 980 litres milk each week at Rs 14 per liter and 1220 liters of milk each week at Rs 16 per liter. Assuming a linear relationship between selling price and demand, how many liters could he sell weekly at Rs 17 per liter.


Find the equations to the straight lines which go through the origin and trisect the portion of the straight line 3 x + y = 12 which is intercepted between the axes of coordinates.


Find the equation to the straight line cutting off intercepts 3 and 2 from the axes.


Find the equation to the straight line which cuts off equal positive intercepts on the axes and their product is 25.


Find the equation of the straight line which passes through the point P (2, 6) and cuts the coordinate axes at the point A and B respectively so that \[\frac{AP}{BP} = \frac{2}{3}\] .


If the straight line \[\frac{x}{a} + \frac{y}{b} = 1\] passes through the point of intersection of the lines x + y = 3 and 2x − 3y = 1 and is parallel to x − y − 6 = 0, find a and b.


Find the equation of the straight line through the point (α, β) and perpendicular to the line lx + my + n = 0.


Find the length of the perpendicular from the origin to the straight line joining the two points whose coordinates are (a cos α, a sin α) and (a cos β, a sin  β).


Find the equations of the straight lines passing through (2, −1) and making an angle of 45° with the line 6x + 5y − 8 = 0.


Find the equations of two straight lines passing through (1, 2) and making an angle of 60° with the line x + y = 0. Find also the area of the triangle formed by the three lines.


Two sides of an isosceles triangle are given by the equations 7x − y + 3 = 0 and x + y − 3 = 0 and its third side passes through the point (1, −10). Determine the equation of the third side.


Find the equation of the straight line drawn through the point of intersection of the lines x + y = 4 and 2x − 3y = 1 and perpendicular to the line cutting off intercepts 5, 6 on the axes.


Find the equation of the straight line which passes through the point of intersection of the lines 3x − y = 5 and x + 3y = 1 and makes equal and positive intercepts on the axes.


Write the area of the triangle formed by the coordinate axes and the line (sec θ − tan θ) x + (sec θ + tan θ) y = 2.


If a, b, c are in G.P. write the area of the triangle formed by the line ax + by + c = 0 with the coordinates axes.


Write the equation of the line passing through the point (1, −2) and cutting off equal intercepts from the axes.


The equation of the straight line which passes through the point (−4, 3) such that the portion of the line between the axes is divided internally by the point in the ratio 5 : 3 is


Find the equation of lines passing through (1, 2) and making angle 30° with y-axis.


In what direction should a line be drawn through the point (1, 2) so that its point of intersection with the line x + y = 4 is at a distance `sqrt(6)/3` from the given point.


Find the equations of the lines through the point of intersection of the lines x – y + 1 = 0 and 2x – 3y + 5 = 0 and whose distance from the point (3, 2) is `7/5`


If a, b, c are in A.P., then the straight lines ax + by + c = 0 will always pass through ______.


The equation of the line joining the point (3, 5) to the point of intersection of the lines 4x + y – 1 = 0 and 7x – 3y – 35 = 0 is equidistant from the points (0, 0) and (8, 34).


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×