English

Find the angle between the lines y = (2-3)(x+5) and y = (2+3)(x-7)

Advertisements
Advertisements

Question

Find the angle between the lines y = `(2 - sqrt(3)) (x + 5)` and y = `(2 + sqrt(3))(x - 7)`

Sum
Advertisements

Solution

The given equations are y = `(2 - sqrt(3))(x + 5)`  .....(i)

And y = `(2 + sqrt(3))(x - 7)`  ...(ii)

Slope of equation (i) m1 (say) = `(2 - sqrt(3))`

And slope of equation (ii) m2 (say) = `(2 + sqrt(3))`

Let θ be the angle between the two given lines

∴ tan θ =  `|(m_1 - m_2)/(1 + m_1m_2)|`

= `|(2 - sqrt(3) - 2 - sqrt(3))/(1 + (2 - sqrt(3))(2 + sqrt(3)))|`

= `|(-2sqrt(3))/(1 + 4 - 3)|`

= `|(-2sqrt(3))/2|`

= `|- sqrt(3)|`

⇒ tan θ = `sqrt(3)` or `- sqrt(3)`

∴ θ = 60° or 120°

shaalaa.com
  Is there an error in this question or solution?
Chapter 10: Straight Lines - Exercise [Page 178]

APPEARS IN

NCERT Exemplar Mathematics Exemplar [English] Class 11
Chapter 10 Straight Lines
Exercise | Q 3 | Page 178

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

The base of an equilateral triangle with side 2a lies along they y-axis such that the mid point of the base is at the origin. Find vertices of the triangle.


Find the slope of the line, which makes an angle of 30° with the positive direction of y-axis measured anticlockwise.


The slope of a line is double of the slope of another line. If tangent of the angle between them is `1/3`, find the slopes of the lines.


If three point (h, 0), (a, b) and (0, k) lie on a line, show that `q/h + b/k = 1`


Consider the given population and year graph. Find the slope of the line AB and using it, find what will be the population in the year 2010?


Find the values of k for which the line (k–3) x – (4 – k2) y + k2 –7k + 6 = 0 is 

  1. Parallel to the x-axis,
  2. Parallel to the y-axis,
  3. Passing through the origin.

Find the equation of a line drawn perpendicular to the line `x/4 + y/6 = 1`through the point, where it meets the y-axis.


Find the slope of a line passing through the following point:

(3, −5), and (1, 2)


State whether the two lines in each of the following are parallel, perpendicular or neither.

Through (5, 6) and (2, 3); through (9, −2) and (6, −5)


Using the method of slope, show that the following points are collinear A (4, 8), B (5, 12), C (9, 28).


What can be said regarding a line if its slope is negative?


The slope of a line is double of the slope of another line. If tangents of the angle between them is \[\frac{1}{3}\],find the slopes of the other line.


Without using the distance formula, show that points (−2, −1), (4, 0), (3, 3) and (−3, 2) are the vertices of a parallelogram.


Find the equations of the straight lines which cut off an intercept 5 from the y-axis and are equally inclined to the axes.


Find the coordinates of the orthocentre of the triangle whose vertices are (−1, 3), (2, −1) and (0, 0).


Find the equations of the altitudes of a ∆ ABC whose vertices are A (1, 4), B (−3, 2) and C (−5, −3).


Find the acute angle between the lines 2x − y + 3 = 0 and x + y + 2 = 0.


If θ is the angle which the straight line joining the points (x1, y1) and (x2, y2) subtends at the origin, prove that  \[\tan \theta = \frac{x_2 y_1 - x_1 y_2}{x_1 x_2 + y_1 y_2}\text { and } \cos \theta = \frac{x_1 x_2 + y_1 y_2}{\sqrt{{x_1}^2 + {y_1}^2}\sqrt{{x_2}^2 + {y_2}^2}}\].


Show that the line a2x + ay + 1 = 0 is perpendicular to the line x − ay = 1 for all non-zero real values of a.


If two opposite vertices of a square are (1, 2) and (5, 8), find the coordinates of its other two vertices and the equations of its sides.


The angle between the lines 2x − y + 3 = 0 and x + 2y + 3 = 0 is


The coordinates of the foot of the perpendicular from the point (2, 3) on the line x + y − 11 = 0 are


If the line joining two points A(2, 0) and B(3, 1) is rotated about A in anticlock wise direction through an angle of 15°. Find the equation of the line in new position.


If the slope of a line passing through the point A(3, 2) is `3/4`, then find points on the line which are 5 units away from the point A.


If one diagonal of a square is along the line 8x – 15y = 0 and one of its vertex is at (1, 2), then find the equation of sides of the square passing through this vertex.


The intercept cut off by a line from y-axis is twice than that from x-axis, and the line passes through the point (1, 2). The equation of the line is ______.


Find the equation of the line passing through the point (5, 2) and perpendicular to the line joining the points (2, 3) and (3, – 1).


The coordinates of the foot of perpendiculars from the point (2, 3) on the line y = 3x + 4 is given by ______.


The point (4, 1) undergoes the following two successive transformations: 
(i) Reflection about the line y = x
(ii) Translation through a distance 2 units along the positive x-axis Then the final coordinates of the point are ______.


One vertex of the equilateral triangle with centroid at the origin and one side as x + y – 2 = 0 is ______.


The points A(– 2, 1), B(0, 5), C(– 1, 2) are collinear.


The vertex of an equilateral triangle is (2, 3) and the equation of the opposite side is x + y = 2. Then the other two sides are y – 3 = `(2 +- sqrt(3)) (x - 2)`.


Line joining the points (3, – 4) and (– 2, 6) is perpendicular to the line joining the points (–3, 6) and (9, –18).


The equation of the line through the intersection of the lines 2x – 3y = 0 and 4x – 5y = 2 and

Column C1 Column C2
(a) Through the point (2, 1) is (i) 2x – y = 4
(b) Perpendicular to the line (ii) x + y – 5
= 0 x + 2y + 1 = 0 is
(ii) x + y – 5 = 0
(c) Parallel to the line (iii) x – y –1 = 0
3x – 4y + 5 = 0 is
(iii) x – y –1 = 0
(d) Equally inclined to the axes is (iv) 3x – 4y – 1 = 0

The three straight lines ax + by = c, bx + cy = a and cx + ay = b are collinear, if ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×