Question

Determine as raízes das funções abaixo:
A) Y=x²- 6x - 16

Answer 1

$\Large\boxed{\begin{array}{l}\sf y=x^2-6x-16\\\sf x^2-6x-16=0\\\sf\Delta=b^2-4ac\\\sf\Delta=(-6)^2-4\cdot1\cdot(-16)\\\sf\Delta=36+64\\\sf\Delta=100\\\sf x=\dfrac{-b\pm\sqrt{\Delta}}{2a}\\\\\sf x=\dfrac{-(-6)\pm\sqrt{100}}{2\cdot1}\\\\\sf x=\dfrac{6\pm10}{2}\begin{cases}\sf x_1=\dfrac{6+10}{2}=\dfrac{16}{2}=8\\\\\sf x_2=\dfrac{6-10}{2}=-\dfrac{4}{2}=-2\end{cases}\\\sf A(8,0)~~B(-2,0)\end{array}}$