zał mianownik nie może być równy 0 a) x≠0 ∧ x-2≠0 x≠2 D=R{0,2} b) x+3≠0 ∧ 5-x≠0 x≠ -3 5≠x D=R{-3,5} c) 4x+3≠0 ∧ 6-x≠0 4x≠ -3 6≠x x≠ -¾ D=R{-¾,6} d) 8x-6≠0 ∧ x+1≠0 8x≠6 x≠ -1 x≠6/8 x≠¾ D=R{-1,¾} e) x(x+6)≠0 x≠0 ∧ x+6≠0 x≠ -6 D=R{-6,0} f) (x-1)(x+3)≠0 (x-1)≠0 ∧ (x+3)≠0 x≠1 ∧ x≠ -3 D=R{-3,1}
a) f(x)=1x+x x-2= x-2+x² x(x-2)= x²+x-2 x(x-2) D=R[0;2] x=0 x=2 b) f(x)=xx+3+25-x= x(5-x)+2(x+3) (x+3)(5-x)= -x²+7x+6 (x+3)(5-x) x=-3 5-x=0 -x=-5(-1) x=5 D=R[-3;5] c) f(x)=x4x+3-56-x= x(6-x)-5(4x+3) (4x+3)(6-x)= 6x-x²-20x-15 (4x+3)(6-x)= -x²-14x-15 (4x+3)(6-x) x=-34 x=6 D=R[-34 ; 6] d) f(x)=x-38x-6-x+7 x+1= (x+1)(x-3)-(x+7)(8x-6) (8x-6)(x+1= x²-2x-3-8x²+6x-56x+42 (8x-6)(x+1)= -7x²-52x+39 (8x-6)(x+1) 8x-6=0 8x=68 x=68 x=34 x=-1 D=R[-1; 34 ] e) f(x)=x²+7 x(x+6)= (x+√7)(x-√7) x(x+6) x=0 x=-6 D=R[-6 ;0] f) f(x)=4x (x-1)(x+3) x-1=0 x+3=0 x=1 x=-3 D=R[-3 ;1]
