Answer:
The values of x are 0 and -4.5
Step-by-step explanation:
To find the inflection point, we simply find the second derivative
Mathematically, that will be calculated as follows
1st derivative
10x^4 + 60x^3
2nd derivative
40x^3 + 180x^2
Equate these values to zero
40x^3 + 180x^2 = 0
x^2(40x + 180) = 0
x^2 = 0
or 40x = -180
x = 0
or x = -180/40 = -4.5
