The maximum of the areas of the isosceles triangles with base on the positive $x$-axis and which lie below the curve $y = e ^ { - x }$ is: (A) $1 / e$ (B) 1 (C) $1 / 2$ (D) $e$
The maximum of the areas of the isosceles triangles with base on the positive $x$-axis and which lie below the curve $y = e ^ { - x }$ is:\\
(A) $1 / e$\\
(B) 1\\
(C) $1 / 2$\\
(D) $e$