Global Maximum for area of a triangle.
I need to find the length of the base of a (isoceles) triangle (x) to get the maximum area in terms of the fixed sides (L)
so far I have found the critical points of the derivative
Area = (1/2) xh
Where h = ( L^2 - (x^2)/4)^1/2
L = Fixed lengths of triangle = constant
So when derivative = 0, we have
Area' = x = L* (2)^1/2
I just need to know how i can test if this is a global maximum of the fucntion.
do i just find the limits when x goes to 0 and infinity? What does it mean when i do?