A negative number wouldn't be reasonable in investments because when you invest you are adding money to something. If you invest you aren't removing anything so there can't be negative numbers.
Answer:
The height of ball when it is at maximum height is 12 unit
Step-by-step explanation:
Given as :
A ball is thrown by child to height y
And y as a function x is y = 
So, for maximum value of height ,
= 0
Or ,
= 0
Or,
= 0
Or,
= 2
or, x = 12
Hence The height of ball when it is at maximum height is 12 unit Answer