Question

Решите уравнение x^4 - 13x^2 + 36 = 0

Answer 1

х^2=t, значит
t^2 - 13t + 36 = 0
D = 25
t1 = 4, t2 = 9

x^2=4
x = 2
x= -2

x^2=9
x = 3
x = -3

Answer 2

Ответ: -3; -2; 2; 3

Answer 3

$x^{4} -13 x^{2} +36=0 \ x^{2} =t \ t^{2} -13t+36=0 \ D=169-144=25 \ sqrt{D} =5 \ t _{1} = frac{13+5}{2} = frac{18}{2} =9 \ t _{2} = frac{13-5}{2} =4 \ x^{2} =9 \ x=+-3 \ x^{2} =4 \ x=+-2$
Ответ: х=-3, х=3
х=-2, х=2