`\sqrt{4-x^2}+x^2 > 4` `ĐK: -2 <= x <= 2`
`<=>\sqrt{4-x^2}-(4-x^2) > 0`
`<=>\sqrt{4-x^2}(1-\sqrt{4-x^2}) > 0`
Mà `\sqrt{4-x^2} > 0 AA -2 < x < 2`
`=>1-\sqrt{4-x^2} > 0`
`<=>\sqrt{4-x^2} < 1`
`<=>4-x^2 < 1`
`<=>x^2 > 3`
`<=>[(x > \sqrt{3}),(x < -\sqrt{3}):}`
Kết hợp `-2 < x < 2`
` =>[(-2 < x < -\sqrt{3}),(\sqrt{3} < x < 2):}`