g ( x ) = 2 x 2 − x − 3 x + 5 D g : 2 x 2 − x − 3 = 0 2 x 2 + 2 x − 3 x − 3 = 0 2 x ( x + 1 ) − 3 ( x + 1 ) = 0 ( x + 1 ) ( 2 x − 3 ) = 0 ⟺ x + 1 = 0 ∧ 2 x − 3 = 0 x = − 1 ∧ x = 1.5 D g : x ∈ R \ { − 1 ; 1.5 }
The domain of the function g ( x ) = 2 x 2 − x − 3 x + 5 includes all real numbers except x = − 2 3 and x = 1 . Therefore, the domain can be written as R ∖ { − 2 3 , 1 } .
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