Answered

Westonci.ca is your trusted source for finding answers to all your questions. Ask, explore, and learn with our expert community. Get expert answers to your questions quickly and accurately from our dedicated community of professionals. Get detailed and accurate answers to your questions from a dedicated community of experts on our Q&A platform.

Find the vertex, focus, and directrix. y = 1/24(x+1)² - 3. 

Sagot :

Lilith
[tex]y = \frac{1}{24}(x+1)^2 - 3\\\\y+3 =\frac{1}{24}(x+1)^2\ \ / *24\\\\ (x+1)^2 = 24(y+3)[/tex]

This   is  an  equation  of  a  parabola  that  opens  upwards.

[tex]Its \ standard \ form: \\(x-h)^2=4p(y-k)\\ (h,k)=(x,y) \ coordinates \ of \ the \ vertex\\\ (h,k)=(-1,-3) \\\\axis \ of \ symmetry: \ x= -1\\ \\4p=24\ \ /:4\\p=6[/tex]

[tex]focus:(h,k+p)=(-1,-3+6)=(-1,3) \\ \\directrix: \ y=k-p=-3-6=-9[/tex]


View image Lilith
[tex] the\ equation\ in\ the\ form\ (x-h)^2=4p(y-k)\ is \ a\ parabola\\with\ a\ vertex\ at\ \ (h,\ k), \\a\ focus\ at\ \ (h,k+p)\\\ and\ a\ directrix\ \ y = k - p \\\\ y = 1/24(x+1)^2 - 3\ \ \ \ \Rightarrow\ \ \ y+3 = 1/24(x+1)^2\ /\cdot24\\\\ 24\cdot(y+3)=(x+1)^2\\\\(x+1)^2=4p(y+3)\ \ \Rightarrow\ \ 4p=24\ \ \Rightarrow\ \ p=6\ \ \ and\ \ \ h=-1,\ k=-3\\\\the\ vertex:\ \ \ (h;\ k)=(-1;\ -3)\\\\the\ focus:\ \ \ (h;\ k+p)=(-1;\ -3+6)=(-1;\ 3)\\\\the\ directrix:\ \ \ y=k-p\ \ \ \Rightarrow\ \ \ y=-3-6=-9 [/tex]