Question

determine as raizes da função y=x²+3x-4.​
Eu preciso da resolução para agora, porfavor respondam.

Answer 1

Vamos encontrar as raízes utilizando a fórmula de Bhaskara.

$y=x^{2} +3x-4\\ \\ a=1~~,~~b=3~~,~~c=-4\\\\ \\ \dfrac{-b\pm\sqrt{b^{2} -4\cdot a\cdot c} }{2\cdot a} ~~\to ~~\dfrac{-3\pm\sqrt{3^{2} -4\cdot 1\cdot (-4)} }{2\cdot 1} ~~\to~~\dfrac{-3\pm\sqrt{25} }{2} ~~\to ~~\dfrac{-3\pm5}{2}\\ \\ \\ \\ \\ x'=\dfrac{-3+5}{2}=\dfrac{2}{2} ~~\to ~~\boxed{x'=1}\\ \\ \\ x''=\dfrac{-3-5}{2}=-\dfrac{8}{2} ~~\to ~~\boxed{x''=-4}$

Raízes:  1  e  - 4

:)