हिंदी

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. - Mathematics

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.

संक्षेप में 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
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 23: The straight lines - Exercise 23.6 [पृष्ठ ४७]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 11
अध्याय 23 The straight lines
Exercise 23.6 | Q 10 | पृष्ठ ४७

संबंधित प्रश्न

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


Find the equation of the straight line passing through (3, −2) and making an angle of 60° with the positive direction of y-axis.


Prove that the perpendicular drawn from the point (4, 1) on the join of (2, −1) and (6, 5) divides it in the ratio 5 : 8.


Find the equation of the line passing through the point (−3, 5) and perpendicular to the line joining (2, 5) and (−3, 6).


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 :

(at1, a/t1) and (at2, a/t2)


By using the concept of equation of a line, prove that the three points (−2, −2), (8, 2) and (3, 0) are collinear.


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 of the straight line which passes through (1, −2) and cuts off equal intercepts on the axes.


Find the equation to the straight line which passes through the point (5, 6) and has intercepts on the axes
(i) equal in magnitude and both positive,
(ii) equal in magnitude but opposite in sign.


Find the equation of the line which passes through the point (− 4, 3) and the portion of the line intercepted between the axes is divided internally in the ratio 5 : 3 by this point. 


A straight line passes through the point (α, β) and this point bisects the portion of the line intercepted between the axes. Show that the equation of the straight line is \[\frac{x}{2 \alpha} + \frac{y}{2 \beta} = 1\].


Find the equation of the line which passes through the point (3, 4) and is such that the portion of it intercepted between the axes is divided by the point in the ratio 2:3.


A straight line drawn through the point A (2, 1) making an angle π/4 with positive x-axis intersects another line x + 2y + 1 = 0 in the point B. Find length AB.


The straight line through P (x1, y1) inclined at an angle θ with the x-axis meets the line ax + by + c = 0 in Q. Find the length of PQ.


Find the equation of the line passing through the point of intersection of the lines 4x − 7y − 3 = 0 and 2x − 3y + 1 = 0 that has equal intercepts on the axes.


Three sides AB, BC and CA of a triangle ABC are 5x − 3y + 2 = 0, x − 3y − 2 = 0 and x + y − 6 = 0 respectively. Find the equation of the altitude through the vertex A.


Find the equation of the line passing through the intersection of the lines 2x + y = 5 and x + 3y + 8 = 0 and parallel to the line 3x + 4y = 7.


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


Find the equation of the straight line perpendicular to 5x − 2y = 8 and which passes through the mid-point of the line segment joining (2, 3) and (4, 5).


Find the equations to the straight lines passing through the point (2, 3) and inclined at and angle of 45° to the line 3x + y − 5 = 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.


Write the integral values of m for which the x-coordinate of the point of intersection of the lines y = mx + 1 and 3x + 4y = 9 is an integer.


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


A line passes through the point (2, 2) and is perpendicular to the line 3x + y = 3. Its y-intercept is


The equation of the line passing through (1, 5) and perpendicular to the line 3x − 5y + 7 = 0 is


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 lines ax + 2y + 1 = 0, bx + 3y + 1 = 0 and cx + 4y + 1 = 0 are concurrent if a, b, c are in G.P.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×