Question

esboce o gráfico da função polinomial do 2°grau f(x)=x²-2x-3

Answer 1

$f(x)=x^2-2x-3 \\ \\ a=1 \\ b=-2 \\ c=-3 \\ \\ Xv= \frac{-b}{2a} = \frac{-(-2)}{2} = \frac{2}{2} =1 \\ \\ X~~|~~ Y \\ 3~~~|~~0~~~~\mapsto(3)^2-2(3)-2=9-6-3=0 \\ 2~~~|-3~~ \mapsto(2)^2-2(2)-3=4-4-3=-3 \\ 1~~~|-4 ~~\mapsto(1)^2-2(1)-3=1-2-3=-4 \\ 0~~~|-3~~\mapsto0^2-2(0)-3=0-0-3=-3 \\ -1|~~0~~~~\mapsto (-1)^2-2(-1)-3=1+2-3=0$