Question
Find the equation of the line through the point (3, 4) which cuts from the first quadrant a triangle of minimum area.
Solution
The equation of any line through P (3, 4) is

where m is slope of line
Put y = 0 in (1)


Let ∆ denote the area of ∆OAB

For
to be maximum or minimum,



which is required equation of line.

where m is slope of line
Put y = 0 in (1)


Let ∆ denote the area of ∆OAB

For




which is required equation of line.