The equation of the line indicates that the x and y-intercept and the formula for the area of the triangle are;
x-intercept (c, 0)
y-intercept (0, 1/(c² + 7))
A(c) = c/(2·(c² + 7))
The steps used to find the x-intercept and the y-intercept are presented as follows;
The equation of the line c·(c² + 7)·y = c - x, can be expressed in the slope intercept form to find the coordinates of the x-intercept and the coordinates of the y-intercept as follows;
c·(c² + 7)·y = c - x
y = (c - x)/(c·(c² + 7))
y = c/(c·(c² + 7)) - x/(c·(c² + 7))
y = 1/((c² + 7)) - x/(c·(c² + 7))
The above equation is in the slope-intercept form, y = m·x + c
Where c is the y-coordinate of the y-intercept, and (0, c) ids the coordinate of the y-intercept; Therefore, the coordinates of the y-intercept is; (0, 1/((c² + 7)))
The coordinate of the x-intercept can be found by plugging in y = 0, in the above equation to get;
0 = 1/((c² + 7)) - x/(c·(c² + 7))
x/(c·(c² + 7)) = 1/((c² + 7))
x = (c·(c² + 7))/((c² + 7))
(c·(c² + 7))/((c² + 7)) = c
x = c
Therefore coordinates of the x-intercept is; (c, 0)
The triangle enclosed by the line and the x-axis and y-axis is a right triangle, therefore;
The positive x and y-values of the x-intercept and y-intercept indicates that the area of the triangle is the product half the distance from the origin to the y-intercept and the distance from the origin to the x-intercept
Area = (1/2) × (1/((c² + 7)) - 0) × (c - 0)
(1/2) × (1/((c² + 7))) × (c) = c/(2·(c² + 7)
Area of the triangle, A(c) = c/(2·(c² + 7)
The complete question found through search can be presented as follows;
Consider the equation of the line c·(c² + 7)·y = c - x where c > 0 is a constant
(a) Find the coordinates of the x-intercept and the y-intercept
x-intercept ( , )
y-intercept ( , )
(b) Find a formula for the area of the triangle enclosed between the line, the x-axis and the y-axis