It is the line of symmetry of a parabola and divides a parabola into two equal halves that are reflections of each other about the line of symmetry.
Answer:
F'=12.1243557 N
Step-by-step explanation:
Let the horizontal component of force he is pulling with be F' Newtons and the force applied be F Newtons.

Answer:
B.
Step-by-step explanation:
Both equations use x squared
B is the answer, because the half of the balls added
When you find any value to x amount of decimal places, you need to go to the term AFTER that to determine the correct value. So, for this, take 61.378 metres. From here, look if the last number is 4 or less. If the number is 4 or less, take the leftmost number off, and you will have your answer (if we had 61.373, the correct answer would be 61.37). If the number is 5 or more, take the leftmost number off, and add 1 to the new leftmost number. Since the last number is 8, the correct answer here is 61.38 metres high. If adding 1 makes the number 10, keep the 0 at the end. So, if you had 61.399, you would make it 61.40