Question

O quadrado menos dobro de um número é igual a -1 calcule esse numero

Answer 1

$\mathtt{x^2 - 2x=-1} \\ \mathtt{x^2 -2x + 1 = 0} \\ \\ \mathtt{a = 1} \\ \mathtt{b = -2} \\ \mathtt{c = 1} \\ \\ \mathtt{\Delta = b^2-4~.~a~. ~c} \\ \mathtt{\Delta = (-2)^2-4~.~1~.~1} \\ \mathtt{\Delta =4 -4 } \\ \mathtt{\Delta =0 } \\ \\ \mathtt{\Delta= 0,~apenas~uma~raiz}$

$\mathtt{\dfrac{-b+-~\sqrt{\Delta}}{2~.~a}~~=~~\dfrac{-(-2) +- 0}{2~.~1}~~=~~\dfrac{2}{2}~~=~~1} \\ \\ \\ \boxed{\boxed{\mathtt{Resposta: 1}}}$