Use the graph from part a to solve the inequality x4 4x3 8

Use the graph from part (a) to solve the inequality

x⁴ ? 4x³ + 8x ? 0.

Express your answer in interval form, with the endpoints rounded to two decimals.

Solution

x^4 - 4x^3 +8x >=0

we have to check from the graph where x^4 - 4x^3 +8x is greater than or equal to zero.

x>= -1 ; 0<= x< = 2 and again x>= 3.2 where the graph is above the x axis

So, solution : ( - inf, -1] U [0 , 2 ] U [ 3.2 , infinity)