Question

f(x)=4x^2+3x-2 

tính f(-1/2)

Answer 1

     `f(x) = 4x^2 + 3x - 2`

Ta có: `f([-1] / 2) = 4 . ([-1] / 2)^2 + 3 . [-1] / 2 -2`

                         `= 4 . 1 / 4 - 3 . 1 / 2 - 2`

                         `= 1 - 3 / 2 - 2 = [-5] / 2`

Answer 2

f(x) = 4 . (-1/2)² + 3.(-1/2) -2

f(x) = 4. 1/4 + (-3/2) -2

f(x) = -5/2

Answer 3

\(f\left(x\right)=4x^2+3x-2\)

\(f\left(\dfrac{-1}{2}\right)=4.\left(\dfrac{-1}{2}\right)^2+3.\left(\dfrac{-1}{2}\right)-2\)

\(f\left(\dfrac{-1}{2}\right)4.\dfrac{1}{4}+3.\left(\dfrac{-1}{2}\right)-2\)

\(f\left(\dfrac{-1}{2}\right)=1+\left(\dfrac{-3}{2}\right)-2\)

\(f\left(\dfrac{-1}{2}\right)=\left(\dfrac{-1}{2}\right)-2\)

\(f\left(\dfrac{-1}{2}\right)=\dfrac{-5}{2}\)