Question

I did A and B I just need help with the rest!

Answer 1

(a) setting f(x) = 0

`\begin{gathered} 3x^4-18x^3-21x^2+144x-108=0 \\ \\ (x+3)(x-1)(x-2)(x-6)=0 \\ \\ \Rightarrow x=-3,1,2,6 \end{gathered}`

(b)

when x = 0

y = f(0) = -108

Hence, the height is 108

(c)

Maximum = (1.5, 15.188)

(d)

Minimum (-1.702, -300) and (4.702, -300)

(e) From the graph, the interval of increasing is

`\begin{gathered} (-1.7,(3)/(2)),(4.7,\infty) \\ \end{gathered}`

(f) From the graph, the interval of decreasing is;

`(-\infty,-1.7),((3)/(2),4.7)`

g)