[latex]P(0,-4)[/latex] [latex]x-4y+8=0[/latex] [latex]-4y=-x-8 /:(-4)[/latex] [latex]y= frac{1}{4}x+2[/latex] reszta w załączniku ================= [latex]y=a(x-p)^2+q[/latex] [latex]W(p,q)[/latex] Odpowiedź [latex]y=(x-4)^2-5[/latex] ================= [latex](x+3)(5x-2)(3x+5)=0[/latex] [latex]x+3=0 lub 5x-2=0 lub 3x+5=0[/latex] [latex]x=-3 lub 5x=2 /:5 lub 3x=-5 /:3[/latex] [latex]. x= frac{2}{5} lub x=- frac{5}{3}[/latex] [latex]-3 cdot frac{2}{5} cdot left(- frac{5}{3} ight)=2[/latex]
y=ax+b x+8=4y/:4 [latex] frac{1}{4}x+2=y [/latex] czyli nasze a=1/4 [latex]y=frac{1}{4}x+b\(0,-4)\-4=frac{1}{4}*0+b \b=-4\y=frac{1}{4}x-4 [/latex] 2) a) nie, bo: [latex]y=(x+4)^{2}-5 \ y= x^{2}+8x+16-5 \ y= x^{2}+8x+11 \ delta= 8^{2}-4*1*11=64-44=20 \ x_{w}= frac{-b}{2a}= frac{-8}{2}=-4 \ y_{w}= frac{-delta}{4a}= frac{-20}{4}=-5 [/latex] b)nie, bo [latex]y=(x-4)^{2}+5 \ y=x^{2}-8x+16+5 \ y= x^{2}-8x+21[/latex] [latex]delta=8^{2}-4*1*21=64-84=-20 \ x_{w}= frac{8}{2}=4 \ y_{w}= frac{20}{4}=5 [/latex] c) tak [latex]y=(x-4)^{2}-5 \ y= x^{2} -8x+16-5 \ y= x^{2} -8x+11 \ delta=64-44=20 \ x_{w}= frac{8}{2}=4 \ y_{w}= frac{-20}{4}=-5 [/latex] 3) (x+3)(5x-2)(3x+5)=0 x=-3 5x-2=0 3x+5=0 5x=2 3x=-5 x=2/5 x=-5/3 -3*2/5*(-5/3)=2