Question

Dada a função f(x) = -x2 +5x+ 6 calcule;
a f (1)
b f(-1)
c f(2)
d f(3)

Answer 1

$f(1) = - {1}^{2} + 5 \times 1 + 6 = \\ = - 1 + 5 + 6 = 10 \\ \\ f( - 1) = - {( -1 )}^{2} + 5( - 1) + 6 = \\ = - 1 - 5 + 6 = 0 \\ \\ f(2) = - {2}^{2} + 5 \times 2 + 6 = \\ = - 4 + 1 0+ 6 = 12 \\ \\ f(3) = - {3}^{2} + 5 \times 3 + 6 = \\ = - 9 + 15 + 6 = 12$