Question:

Find the equation of the line that passes though \((2, 2\sqrt 3)\) and is inclined with the x-axis at an angle of 75°.

Updated On: Oct 25, 2023
Hide Solution
collegedunia
Verified By Collegedunia

Solution and Explanation

The slope of the line that inclines with the x-axis at an angle of 75° is
\(m = tan \ 75°\)
⇒ \(m=tan(45°+30°)\) = \(\frac {tan\ 45°+tan\ 30°}{1-tan\ 45°tan\ 30°}\) = \(\frac {1+\frac {1}{\sqrt 3}}{1-1.\frac {1}{\sqrt 3}}\)\(\frac {\sqrt 3+1}{\sqrt 3-1}\)
We know that the equation of the line passing through point \((x_0, y_0)\), whose slope is m, is \((y-y_0)=m(x-x_0)\)
Thus, if a line passes though \((2,2\sqrt 3)\) and inclines with the x-axis at an angle of 75°, then the equation of the line
is given as

Was this answer helpful?
0
0

Concepts Used:

Straight lines

A straight line is a line having the shortest distance between two points. 

A straight line can be represented as an equation in various forms,  as show in the image below:

 

The following are the many forms of the equation of the line that are presented in straight line-

1. Slope – Point Form

Assume P0(x0, y0) is a fixed point on a non-vertical line L with m as its slope. If P (x, y) is an arbitrary point on L, then the point (x, y) lies on the line with slope m through the fixed point (x0, y0) if and only if its coordinates fulfil the equation below.

y – y0 = m (x – x0)

2. Two – Point Form

Let's look at the line. L crosses between two places. P1(x1, y1) and P2(x2, y2)  are general points on L, while P (x, y) is a general point on L. As a result, the three points P1, P2, and P are collinear, and it becomes

The slope of P2P = The slope of P1P2 , i.e.

\(\frac{y-y_1}{x-x_1} = \frac{y_2-y_1}{x_2-x_1}\)

Hence, the equation becomes:

y - y1 =\( \frac{y_2-y_1}{x_2-x_1} (x-x1)\)

3. Slope-Intercept Form

Assume that a line L with slope m intersects the y-axis at a distance c from the origin, and that the distance c is referred to as the line L's y-intercept. As a result, the coordinates of the spot on the y-axis where the line intersects are (0, c). As a result, the slope of the line L is m, and it passes through a fixed point (0, c). The equation of the line L thus obtained from the slope – point form is given by

y – c =m( x - 0 )

As a result, the point (x, y) on the line with slope m and y-intercept c lies on the line, if and only if

y = m x +c