Answered

Quais são os zeros(ou raízes) da função quadrática f(x) = x² + 3x - 4? Assinale a alternativa correta. *
a) 2 e 3
b) 1 e - 4
c) 3 e 4
d) 4 e -1

Answer :

Given:

The quadratic function is:

[tex]f(x)=x^2+3x-4[/tex]

To find:

The zeros of the given quadratic function.

Solution:

We have,

[tex]f(x)=x^2+3x-4[/tex]

Splitting the middle term, we get

[tex]f(x)=x^2+4x-x-4[/tex]

[tex]f(x)=x(x+4)-1(x+4)[/tex]

[tex]f(x)=(x+4)(x-1)[/tex]

For zeros, [tex]f(x)=0[/tex].

[tex](x+4)(x-1)=0[/tex]

[tex]x=-4,1[/tex]

Therefore, the correct option is (b).

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