Question

#12

EXERCISE SET 15.3 Toto In Exercises 7-12, determine the coordinates of the focus and the equation of the directrix of each narabola. State the direction in which each parabola opens and sketch each curve. 1/2 = 4y 4. y2 = -20x 7. y = 10x 10.x = -17y 2. x = 12y O 5.x = -8y) 11. y = -21x 3. 7= - 4x m 6. x = -16y 9. - 2y be 12. y 3x l o storima b) gidential dvd v ol Tol 8. y = -14x2

Answer 1

Question -12

.

y = 5.2

5.x = y

$4\cdot \frac{5}{4}x=y^2$

4.5(x ) = (y – 0)

compare this equation with

4p(x - h) = (y-2)

so here

h=0, k=0, p=7

.

coordinate of foci is

(+0) = (y*d +9)

(h+p, k) =

.

and the equation of directrix is

x=h-

T = ( - الت | ظ

${\color{Red} x=-\frac{5}{4}}$

.

X=-5/4 (5/4,0)