Question

Sa se calculeze x1+x2+x1x2 , stiind ca x1si x2 sunt solutiile ecuatiei x2-2x-2=0

Answer 1

x²-2x-2 =0
Δ=(-2)²-4 (-2)= 4+8 =12
x1= (2+√12)/2=( 2 + 2√3)/2= 1+√3
x2=(2-√12)/2 = (2-2√3)/2 = 1-√3

x1 +x2 +x1x2= 1+√3 +1-√3 + (1+√3)(1-√3) = 2 + (1-3) = 2 -2 =0