Question

Dada a função f, tal que
f (x) = -x²+5x+6
calcule:

a) f($\sqrt{2}$)
b) f($\frac{-4}{5}$)
c) f( $\frac{49}{4}$)

Answer 1

a) f = -(√2)² + 5 . (√2) + 6
    f = -2 + 5√2 + 6
    f = 5√2 + 4

b) f = -(-4/5)² + 5 . (-4/5) + 6
    f = -16/25 - 4 + 6
    f = 34/25

c) f = -(49/4)² + 5 . (49/4) + 6
    f = - 2401/16 + 245/4 + 6
    f = -1421/16 + 6
    f = -1325/16