Question

Решите уравнение
a) 1/4x^2=0,16
b) x^3-4x^2-x+4=0

Answer 1

а)

$displaystyle tt frac{1}{4}x^2=0,16 : : : : | cdot 4\displaystyle tt x^2=0,64\displaystyle tt x=sqrt{0,64}\displaystyle tt x_1=0,8\displaystyle tt x=-sqrt{0,64}\displaystyle tt x_2=-8$

б)

$displaystyle tt x^3-4x^2-x+4=0\displaystyle tt x^2(x-4)-(x-4)=0\displaystyle tt (x-4)(x^2-1)=0\displaystyle tt x-4=0\displaystyle tt x_1=4\displaystyle tt x^2-1=0\displaystyle tt x^2=1\displaystyle tt x=sqrt{1}\displaystyle tt x_2=1\displaystyle tt x=-sqrt{1}\displaystyle tt x_3=-1$