WILL MARK BRAINLIEST IF YOUR ANSWERS ARE CORRECT 1. what are the focus and the directrix to a parabola and how do they help you understand about a parabola ?

2. how are the center, radius, and a point on the circle expressed algebraically?

 1. What are the focus and directrix of a parabola? Parabolas are commonly known as the graphs of quadratic functions. They can also be viewed as the set of all points whose distance from a certain point (the focus) is equal to their distance from a certain line (the directrix).

2.The center-radius form is: (x−h)2+(y−k)2=r2 Here, the center point is denoted by (h,k) and r is the radius of the circle.

Step-by-step explanation:

3-4

step-by-step explanation:

the answer is 3-4 because both 45 and 60 has a multiple of 15.

45/3=15

60/4=15

therefore the odds against selecting a red is 4-3

the radius is 2 times the diameter.

step-by-step explanation: