Question

encontrar as raízes da função f(x)=x2+4x-5?

Answer 1

$f(x)= x^{2} +4x-5 \\\\ a=1; b=4;c=-5 \\\\ \Delta= b^{2} -4.a.c \to \Delta= 4^{2} -4.1.(-5) \to \Delta=16+20 \to \Delta =36 \\\\ x= \frac{-b+- \sqrt{\Delta} }{2.a} \to x= \frac{-4+- \sqrt{36} }{2.1} \to x= \frac{-4+-6}{2} \\\\x'= \frac{-4+6}{2} \to x'= \frac{2}{2} \to x'= 1\\ \\x''= \frac{-4-6}{2} \to x''= \frac{-10}{2} \to x''=-5\\\\\\S=(-5;1)$