Question

Dada a função () = + e sabendo que (3) = 5 e (−2) = −5, calcule (1/2)

Answer 1

f(x) ax + b

f(3) = 5       →  ( 3 ; 5 )

f(-2) = -5    →  ( -2 ; -5 )

f(1/2) = ?

a = ( 5 - (-5) ) ÷ ( 3 - (-2) ) = ( 5 + 5 ) ÷ ( 3 + 2 ) = 10 ÷ 5 = 2

f(x) = 2x + b  ⇔ 5 = 2 × 3 + b ⇔ 5 = 6 + b ⇔ b = 5 - 6 ⇔ b = -1

f(x) = 2x - 1

f(1/2) = 2 × (1/2) - 1 = 1 - 1 = 0