Directrix

Q. The equation of the directrix of the parabola $y^2+4y+4x+2=0$ is

1. $x=-1$
2. $x=1$
3. $x=-\frac{3}{2}$
4. $x=\frac{3}{2}$

Q.

What is the focus and directrix of a parabola?

Q. The equation of the directrix of the parabola whose vertex (3, 2) and focus (2, –1) is

1. x + 3y – 19 = 0
2. y - 2y – 9 = 0
3. 2x + 6y – 24 = 0
4. x – 3y – 19 = 0

Q.

The equation of the directrix of the parabola $x^2-4x-3y+10=0$ is

1. $y=-\frac{5}{4}$

2. $y=\frac{5}{4}$

3. $y=-\frac{3}{4}$

4. $x=\frac{5}{4}$

Q. The equation of parabola, whose axis is parallel to $y-$axis and which passes through points $(0,2),(-1,0)$ and $(1,6)$ is

1. $y=x^2+3x+2$
2. $y=x^2+3x-2$
3. $x^2+3y+2=0$
4. $y^2+3x+2=0$

Q.

The locus of the mid-point of the line segment joining the focus ot a moving point on the parabola $y^2=4ax$ is another parabola with directrix

1. $x=-a$

2. $x=-\frac{a}{2}$

3. $x=0$

4. $x=\frac{a}{2}$

Q.

The Equation of the directrix to parabola $y^2=8x$ is _____

1. $x+2=0$

2. $x+3=0$

3. $x+1=0$

4. $x=0$

Q.

The locus of a point whose chord of contact with respect to parabola
$y^2=8x$ passes through focus is

1. $x+2=0$

2. Directrix of the given parabola

3. $x+1=0$

4. Latus ractum of the given parabola

Q. For hyperbola $-\frac{x^2}{16}+\frac{y^2}{25}=1$ distance between directrices is

1. $\frac{50}{\sqrt{41}}$
2. $\frac{16}{\sqrt{41}}$
3. $\frac{25}{\sqrt{41}}$
4. $\frac{32}{\sqrt{41}}$

Q. If the focus of the parabola $(y-\beta {)}^2=4(x-\alpha )$ always lies between the lines $x+y=1$ and $x+y=3$ then

1. $1<\alpha +\beta <3$
2. $0<\alpha +\beta <3$
3. $0<\alpha +\beta <2$
4. $-1<\alpha +\beta <2$

Q. The mirror image of the directrix of the parabola $y^2=4(x+1)$ in the line mirror $x+2y=3$ is

1. $x=-2$
2. $4y+3x=16$
3. $3x-4y+16=0$
4. none of these