Question

1.Aflati solutiile intregi ale ecuatiei x² +x+1=3
2. Calculati sin²135+ cos²45
3. Fie f:R->R ; F(x)= x²+1, rezolvati inecuatia f(x)

Answer 1

1.
$x^2+x+1=3 \\ x^2+x-2=0 \\ D= 1-4*(-2)=9 \\ x_1= \frac{-1+ \sqrt{9} }{2}=1 \\ x_2= \frac{-1- \sqrt{9} }{2}=-2$

2.
$sin135^o=sin45^o \\ Calculul\ devine: \\ sin^245^o+cos^245^o=1$

3.
Enunt incomplet al problemei.