Find the minimum value of the function y = x(1+x)
A
-1/4
B
-1/2
C
1/4
D
1/2
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
y = x(1+x)
= x + x2
dy/dx = 1 + 2x
As dy/dy → 0
1 + 2x = 0
2x = -1
X = -1/2
Y = x(1+x)
= -1/2(1 - 1/2) at x = -1/2
= -1/2(1/2)
= -1/4
Source: Myschool Past Questions Archive (Record #9290)