Question

Determine as raízes da função f(x)=x2-x-2

Answer 1

Explicação passo-a-passo:

$f(x)=x^2-x-2$

$f(x)=0$

$x^2-x-2=0$

$\Delta=(-1)^2-4\cdot1\cdot(-2)$

$\Delta=1+8$

$\Delta=9$

$x=\dfrac{-(-1)\pm\sqrt{9}}{2\cdot1}=\dfrac{1\pm3}{2}$

$x'=\dfrac{1+3}{2}~\Rightarrow~\boxed{x'=2}$

$x"=\dfrac{1-3}{2}~\Rightarrow~\boxed{x"=-1}$