Question

Sa se rezolve ecuatiile in C:
a) $2x^2 - 2 x+1=0$
b) $x^2 + 6x+10=0$
c)$x^2 + x +1=0$
d)$x^2 -10x+26=0$
e)$9x^2-12x+13=0$

Answer 1

$\Delta=b^2-4ac;\ x_{1;2}=\dfrac{-b\pm\sqrt{\Delta}}{2a}$

a) $\Delta=-4\Rightarrow x_{1;2}=\dfrac{2\pm2i}{4}=\dfrac{1\pm i}{2}$

b)$\Delta=-4\Rightarrow x_{1;2}=\dfrac{-6\pm2i}{2}=-3\pm i$

c) $\Delta=-3\Rightarrow x_{1;2}=\dfrac{-1\pm i\sqrt3}{2}$

d) $\Delta=-4\Rightarrow x_{1;2}=\dfrac{10\pm2i}{2}=5\pm i$

e) $\Delta=-324\Rightarrow x_{1;2}=\dfrac{12\pm18i}{18}=\dfrac{2\pm3i}{3}$