Given curve condition, \[y\text{ }=\text{ }b\text{ }.\text{ }e-x/an\] and line condition \[x/a\text{ }+\text{ }y/b\text{ }=\text{ }1\]
Presently, let the directions of where the curve meets the y-axis be (0, y1)
Presently separating \[y\text{ }=\text{ }b\text{ }.\text{ }e-x/a\] the two sides w.r.t. x, we get
In this way, the condition of the curve crosses at \[\left( 0,\text{ }b \right)\] which is on the y-axis.