Răspuns:
2) [tex]f(x)= x^2-m*x+m-1[/tex]
[tex]\frac{-b}{2a}= -1 <=> \frac{-(-m)}{2*1} = \frac{m}{2} = -1 => m = -2[/tex]
3) [tex]x^2-7x+20 = 0 ; a = 1 ; b = -7 ; c = 20\\[/tex]
[tex]Suma = x1+x2 = \frac{-b}{a} = \frac{7}{1} = 7[/tex] (din relatiile lui Viette)
[tex]Produsul = x1*x2 = \frac{c}{a} = \frac{20}{1} = 20[/tex]
[tex](x1+x2)+(x1*x2) = 7 + 20 = 27[/tex]
4) Gf intersectat cu Ox => y = f(x) = 0 => [tex]2x^2-3x+1= 0 <=> 2x^2-x-2x+1 = x(2x-1)-1(2x-1) = (2x-1)(x-1)\\=> x1 = 1 ; x2 = 1/2[/tex]
=> A(1; 0) si B(1/2 ; 0)
Gf intersectat cu Oy => x = 0 => f(0) = [tex]2*0^2 - 3*0 + 1 = 1[/tex] => C (0; 1)
Explicație pas cu pas:
