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The graph of f(x) = x6 – 2x4 – 5x2 + 6 is shown below. How many roots of f(x) are rational numbers? 1

Respuesta :

Answer:

1,-1 are rational numbers

Step-by-step explanation:

Given equation: [tex]f(x) = x^6-2x^4-5x^2+6[/tex]

Roots of f(x) are : [tex]x^6-2x^4-5x^2+6=0[/tex]

⇒ [tex](x-1)(x+1)(x^2-3)(x^2+2)[/tex]

⇒ [tex](x-1)(x+1)(x+\sqrt{3})(x-\sqrt{3})(x+\sqrt{2})(x-\sqrt{3})[/tex]

⇒[tex](x=1)(x=-1)(x=\sqrt{3})(x=-\sqrt{3})(x=\sqrt{2})(x=-\sqrt{2})[/tex]

⇒[tex]x=1,-1,\sqrt{3},-\sqrt{3},\sqrt{2},-\sqrt{2}[/tex]

from these roots only -1,1 is consider as rational numbers as all integers are rational numbers.

Rest [tex]x=\sqrt{3},-\sqrt{3},\sqrt{2},-\sqrt{2}[/tex] are irrational numbers.

Answer:

B

Step-by-step explanation:

the roots would be 1 and -1 when it comes to the graph