H ( x ) = x 2 + 1 ; K ( x ) = − x 2 + 4 K ( H ) = K ( x 2 + 1 ) = − ( x 2 + 1 ) 2 + 4 = 0 ( x 2 + 1 ) 2 = 4 ⟺ x 2 + 1 = ± 4 x 2 + 1 = − 2 or x 2 + 1 = 2 ∣ s u b t r a c t 1 f ro m b o t h s i d es x 2 = − 3 or x 2 = 1 x = ± i 3 or x = ± 1
The roots of the equation K ( H ) = 0 are ± i 3 and ± 1 . Therefore, the possible answers are A and D. However, since A is presented as a single option, we highlight the roots ± i 3 .
;