# Consider the equation of the parabola: 2y = −y − 8x + 11. FINAL EXAM REVIEW QUESTION?

Consider the equation of the parabola: 2y = −y − 8x + 11.

(a) Complete the square to place the equation in standard form.

b) State the coordinates of the vertex.

(c) State the coordinates of the focus.

d) State the equations of the directrix and axis of symmetry.

a) I got -8x-3/2=y+1^2 (i' not too sure about my answer for (a)) correct me pls

b) i got (3/2, -1)

c) i got (-1/2,-1)

d) i got x=7/2

If any is incorrect please correct me thanks

the equation is 2y = −y^2− 8x + 11

### 3 Answers

- AlanLv 77 months agoFavourite answer
a) Complete the square to place the equation in standard form.

You don't complete the square to place in standard form

you complete the square to put in Vertex form

-8x = y^2 + 2y -11

-8x = (y+1)^2 - 1 - 11

Vertex form

x = (-1/8)(y+1)^2 + 12/8

x = (-1/8) (y+1)^2 + 1.5

Conical form

(x- 1.5 ) = (-1/8)(y+1)^2

-8(x+1.5) = (y+1)^2

so here 4p = -8

p = -2

b) State the coordinates of the vertexVertex (1.5, -1) .(c) State the coordinates of the focus.(1.5, -1) is the vertex the focus is p units away from (1.5 ,-1 ) along y =-1 focus( -0.5, -1 )d) State the equations of the directrix and axis of symmetry.y = -1 is the axis of symmetry

directix is perpdencular to the axis of symmetry and p units

in the opposite direction of the focus

x= 1.5 + 2 = 3.5

x = 3.5 is the directrix