हिंदी

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±3)(x-2).

Advertisements
Advertisements

प्रश्न

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)`.

विकल्प

  • True

  • False

MCQ
सत्य या असत्य
Advertisements

उत्तर

This statement is True.

Explanation:

Let ABC be an equilateral triangle with vertex (2, 3) and the opposite side is x + y = 2 with slope –1.

Suppose slope of line AB is m.

Since each angle of equilateral triangle is 60°.

∴ Angle between AB and BC

tan 60° = `|(-1 - m)/(1 + (-1)m)|`

⇒ `sqrt(3) = |(1 + m)/(1 - m)|`

⇒ `sqrt(3) = +- ((1 + m)/(1 - m))`

Taking (+) sign,

`sqrt(3) = (1 + m)/(1 - m)`

⇒ `sqrt(3) - sqrt(3)m = 1 + m`

⇒ `sqrt(3)m + m = sqrt(3) - 1`

⇒ `m(sqrt(3) + 1) = sqrt(3) - 1`

⇒ `m = (sqrt(3) - 1)/(sqrt(3) + 1)

⇒ `m = (sqrt(3) - 1)/(sqrt(3) + 1) xx (sqrt(3) - 1)/(sqrt(3) - 1)`

⇒ `m = (3 + 1 - 2sqrt(3))/(3 - 1)`

= `2 - sqrt(3)`

Taking (–) sign,

`m = 2 + sqrt(3)`

So, the equations of other two lines are y – 3 = `(2 +- sqrt(3))(x - 2)`

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 10: Straight Lines - Exercise [पृष्ठ १८३]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
अध्याय 10 Straight Lines
Exercise | Q 52 | पृष्ठ १८३

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

Find the slope of a line, which passes through the origin, and the mid-point of the line segment joining the points P (0, –4) and B (8, 0).


Find the angle between the x-axis and the line joining the points (3, –1) and (4, –2).


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


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


What is the value of y so that the line through (3, y)  and (2, 7) is parallel to the line through (−1, 4) and (0, 6)?


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


Show that the line joining (2, −5) and (−2, 5) is perpendicular to the line joining (6, 3) and (1, 1).


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 angle between X-axis and the line joining the points (3, −1) and (4, −2).


By using the concept of slope, show that the points (−2, −1), (4, 0), (3, 3) and (−3, 2) are the vertices of a parallelogram.


Find the equations of the bisectors of the angles between the coordinate axes.


Find the equation of the perpendicular to the line segment joining (4, 3) and (−1, 1) if it cuts off an intercept −3 from y-axis.


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


Show that the perpendicular bisectors of the sides of a triangle are concurrent.


Find the equation of the right bisector of the line segment joining the points (3, 4) and (−1, 2).


Find the image of the point (3, 8) with respect to the line x + 3y = 7 assuming the line to be a plane mirror.


Find the angle between the line joining the points (2, 0), (0, 3) and the line x + y = 1.


Find the tangent of the angle between the lines which have intercepts 3, 4 and 1, 8 on the axes respectively.


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 reflection of the point (4, −13) about the line 5x + y + 6 = 0 is  


Find k, if the slope of one of the lines given by kx2 + 8xy + y2 = 0 exceeds the slope of the other by 6.


If x + y = k is normal to y2 = 12x, then k is ______.


Point of the curve y2 = 3(x – 2) at which the normal is parallel to the line 2y + 4x + 5 = 0 is ______.


Find the equation of the straight line passing through (1, 2) and perpendicular to the line x + y + 7 = 0.


A ray of light coming from the point (1, 2) is reflected at a point A on the x-axis and then passes through the point (5, 3). Find the coordinates of the point A.


The two lines ax + by = c and a′x + b′y = c′ are perpendicular if ______.


Show that the tangent of an angle between the lines `x/a + y/b` = 1 and `x/a - y/b` = 1 is `(2ab)/(a^2 - b^2)`


Find the equation of a straight line on which length of perpendicular from the origin is four units and the line makes an angle of 120° with the positive direction of x-axis.


The equation of the straight line passing through the point (3, 2) and perpendicular to the line y = x is ______.


Equation of the line passing through (1, 2) and parallel to the line y = 3x – 1 is ______.


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×