Question

considere o polinômio p(x) = det ( x(x + 1) −1 −x − 3 x + 1 ). qual o valor de p(2)?

Answer 1

$\displaystyle \sf f(x) = det\left[\begin{array}{cc}\sf x(x+1)&-1\\\sf -x-3&\sf x+1\end{array}\right] \ \ \ ;\ f(2) =\ ?\\\\\\\ \underline{\text{Determinante }}: \\\\\ f(x) = x( x+1)\cdot (x+1) - (-x-3)\cdot(-1) \\\\ f(x) = x\cdot(x+1)^2-x-3 \\\\ f(2) = 2\cdot(2+1)^2-2-3\\\\ f(2) = 2\cdot 3^2-5\\\\ f(2) = 2\cdot 9-5\\\\ \huge\boxed{\sf f(2) = 13}\checkmark$

letra B