Question

x^4+11x^2-28=0
Помогите решить.

Answer 1

$x^4 +11x^2-28 =0\\ x^4 + 11x^2 + frac{121}{4} - frac{233}{4} = 0\\ (x^2 + frac{11}{2})^2 - frac{233}{4} = 0\\ (x^2 + frac{11}{2} - frac{sqrt{233}}{2})(x^2 + frac{11}{2} + frac{sqrt{233}}{2}) = 0\\ x^2 + frac{11}{2} - frac{sqrt{233}}{2} = 0\\ boxed{mathbb{OTBET}: x = pmsqrt{frac{sqrt{233}}{2} - frac{11}{2}}}$