Question 914978
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Hi
a zero of the function f(x) = 4x^4 - 8x^3 - 19x^2 + 23x - 6 is:  x = -2
(x+2) a factor
Using Synthetic Division
					
-2	4	-8	-19	23	-6
		-8	32	-26	6
	4	-16	13	-3	0
 4x^3 - 16x^2 - 13x - 3 (3 a zero of this)
					
3	4	-16	 13	-3
		12	-12	3	
	4	-4	1	0	0
(x+2)(x-3)(4x^2 - 4x + 1) = (x+2)(x-3)(2x-1)^2
roots: -2, 3, 1/2(multiplicity of two)

{{{drawing(300,300,   -6, 6, -100,100, grid(1), 

graph( 300, 300, -6, 6, -100,100,0, 4x^4 - 8x^3 - 19x^2 + 23x - 6 ) )}}}