Question

Hàm số \(y=f\left(x\right)\) được cho bởi công thức \(f\left(x\right)=2x^2-5\)

Hãy tính : \(f\left(1\right);f\left(-2\right);f\left(0\right);f\left(2\right)\) ?

Answer 1

f (1) = 2 . 1² - 5 = -3

f (-2) = 2 . (-2)² - 5 = 3

f (0) = 2 . 0² - 5 = -5

f (2) = 2 . 2² - 5 = 3

Answer 2

Có: \(f\left(x\right)=2x^2-5\)

\(\Rightarrow f\left(1\right)=2.1^2-5=-3\)

\(f\left(-2\right)=2.\left(-2\right)^2-5=3\)

\(f\left(0\right)=2.0^2-5=-5\)

\(f\left(2\right)=2.2^2-5=3\)