Question

Решите уравнение: х^4 - 3х^2 -4 =0

Answer 1

${x}^{4} - 3 {x}^{2} - 4 = 0 \ {x}^{2} = t \ {t}^{2} - 3t - 4 = 0 \ d = 9 - 4 times 1 times ( - 4) = 25 \t = frac{3 + - 5}{2} \ t1 = - 1 \ t2 = 4 \ {x}^{2} = 4 \x = + - 2$
x^2 не может быть равно -1