Answer:

Step-by-step explanation:
we are given an algebraic function in x, such that

To find when second derivative >0
For this let us find first and second derivative by successive differentiation.

when ii derivative >0 we have
60x^3-30>0

f"(x)>0 in

They all look good except for 4 5 and 6 switch them
Answer:
A
Step-by-step explanation:
Cost of most expensive product = $40
total money spent at the store
= 18 + 22 + 35
= 75