Step 1:

The polynomial is $\"\"$ .

It is possible to find the roots of this polynomial using graphically.

Graph :

The graph of the polynomial, real roots are x-intercept of the graph of $\"\"$ .

$\"\"$

Graphically the roots of the polynomial are $\"\"$ .

Step 2:

To find the remaining two roots, reduce the polynomial using synthetic division method.

Make a table for synthetic division method :

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

roots	2	-3	-17	41	-21
-3.285	2	-9.57	14.44	-6.42	0.14

The reduced polynomial is $\"\"$

Again make a table for synthetic division method :

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

roots	2	-9.57	14.44	-6.42
0.784	2	-8.01	8.2	0.02

The reduced polynomial is $\"\"$ .

Step 3:

The roots of the quadratic equation $\"\"$ are $\"\"$ .

The quadratic equation is $\"\"$ .

$\"\"$

The roots of the quadratic equation is $\"\"$ .

Solution :

The roots of the polynomial $\"\"$ is $\"\"$ , $\"\"$ .