The angle between the positive horizontal axis and a given line is 135o. Find the equation of the line if it passes through the point (2,3)
Answer Details
The problem requires finding the equation of a line that passes through a given point (2,3) and makes an angle of 135 degrees with the positive x-axis.
To solve this problem, we need to first find the slope of the line. Since the given angle is measured from the positive x-axis and is 135 degrees, we know that the angle made with the negative x-axis is 45 degrees. Therefore, the slope of the line is the tangent of 45 degrees, which is 1.
Now that we have the slope, we can use the point-slope form of the equation of a line to find the equation of the line. The point-slope form is:
y - y1 = m(x - x1)
where m is the slope and (x1, y1) is a point on the line. Plugging in the values we have, we get:
y - 3 = 1(x - 2)
Simplifying this equation gives us:
y - x + 3 = 0
This equation is in the form of y = mx + b, where m is the slope and b is the y-intercept. We can see that the slope is 1, which we found earlier, and the y-intercept is 3.
Therefore, the equation of the line that passes through the point (2,3) and makes an angle of 135 degrees with the positive x-axis is:
y - x + 3 = 0
which is equivalent to:
y = x - 3
So, the answer is neither (a) nor (b), but is (c) x + y = 5.