Question

f: R⇒R
f(x)= x²+6x+7
x²+6x+7=0
Δ=6²-4*1*7=36-28=8>0
mai departe?

Answer 1

$\left \{ {{ x_{1}= \frac{(-6 + \sqrt{8}) }{2} } \atop {x_{2}= \frac{(-6 - \sqrt{8}) }{2}}} \right.$
$\left \{ {{ x_{1}= \frac{-6+ 2\sqrt{2} }{2} } \atop {{{ x_{2}= \frac{-6- 2\sqrt{2} }{2}}} \right.$
$\left \{ {{ x_{1}= \frac{2(-3 + \sqrt{2}) }{2} } \atop {{{ x_{2}= \frac{2(-3 - \sqrt{2}) }{2}}} \right.$
$\left \{ {{ x_{1}=-3 + \sqrt{2} } \atop {{{ x_{2}=-3 - \sqrt{2}}} \right.$