Answer:
9
Step-by-step explanation:
let's assume ;
12=a
15=c
?=b
so;
a2+b2=c2
(12)2+b2=(15)2
144+b2=225
b2=225-144
b2=81 (square root both sides)
You'll get
b=9
NB; 2 is used as squared
I think is B but idk how to do this but I could try
Answer:
Choice D is correct
Step-by-step explanation:
The first step is to write the polar equation of the conic section in standard form by dividing both the numerator and the denominator by 2;

The eccentricity of this conic section is thus 1, the coefficient of cos θ. Thus, this conic section is a parabola since its eccentricity is 1.
The value of the directrix is determined as;
d = k/e = 3/1 = 3
The denominator of the polar equation of this conic section contains (-cos θ) which implies that this parabola opens towards the right and thus the equation of its directrix is;
x = -3
Thus, the polar equation represents a parabola that opens towards the right with a directrix located at x = -3. Choice D fits this criteria