Question

2) A respeito da função f(x) = – 4x2 + 100, assinale a alternativa que seja o resultado da soma entre as coordenadas x e y do vértice. *​

Answer 1

$\sf{\Delta=b^2-4ac}\\\sf{\Delta=100^2-4\cdot(-4)\cdot0=10000}\\\sf{x_V=-\dfrac{b}{2a}=-\dfrac{\diagdown\!\!\!\!100}{2\cdot(-\diagdown\!\!\!\!4)}}\\\sf{x_V=\dfrac{25}{2}}\\\sf{y_V=-\dfrac{\Delta}{4a}=-\dfrac{10000}{4\cdot4}}\\\sf{y_V=-\dfrac{10000}{16}=625}$

$\sf{x_V+y_V=\dfrac{25}{2}+625=\dfrac{1275}{2}}$