When you are doing derivatives, you don't want to do it right away because there is still ( ) we need to remove that first get,
g(x)=3x^4-6x
Now we can do the derivatives!
g(x)=12*x^3 - 6
I hope this helps!
Y-INTERCEPT

The y-intercept is where the equation/curve/parabola cosses the y-axis.
The y-axis is where x = 0. (The x-axis is where y = 0)
To find the y-intercept:

The y-intercept must be at (0, 10)
X-INTERCEPT (ROOTS/SOLUTIONS)

We need to use the quadratic formula
The quadratic formula helps us find what values of
make the equation = 0
Quadratic formula: 

The x-intercepts are at:

19/4 = 4 3/4 ft which is less than 5ft
Yes she has room