Part 1: The general form for this matches y^2 = -4cx, which implies that this opens to the left. (Imagine assigning any value of y, whether positive or negative, which would result in a positive left-hand value. Then to match this sign, the value of x must be negative so that the right-hand side becomes positive as well.)
Part 2: The distance from the vertex to the directrix is given by c. This equation has its vertex at the origin (0, 0). If it opens to the left, the directrix is a vertical line to the right of the origin. This equation is y^2 = -4(1/2)x, so c = 1/2, and the directrix has the equation x = 1/2.
Part 3: The focus is inside the parabola, but it is the same distance from the vertex as the directrix. This distance is 1/2 units, and it will be to the left of the vertex. So the focus is at (-1/2, 0).
#4) 1/6
#5) 1/2
#6) 4/15
#7) 8/15
#8) 11/15
#9) 12
#10) 15
#11) 112
Explanation
#4) There is one section marked 5 out of 6 sections.
#5) There are three odd-numbered sections out of 6 sections.
#6) 2 blue were tossed 4 times out of 15 tosses.
#7) 1 blue and 1 pink were tossed 8 ties out of 15 tosses.
#8) All blue was tossed 4 times out of 15; this means that all blue was not tossed 15-4=11 times out of 15.
#9) There are 4 choices for location and 3 choices for transportation; 4(3) = 12.
#10) There are 3 choices for level and 5 choices for character; 3(5) = 15.
#11) Since 30% are rock, 100%-30% = 70% are not rock. 70% = 70/100 = 0.7; 0.7*160 = 112.
Answer:
A. x > -1
Step-by-step explanation:
- (x - 3) < 4 (2 + x)
-x + 3 < 8 + 4x
-5x + 3 < 8
-5x < 5
x > -1
Therefore, answer choice A is the correct answer.
Answer:
11 17/21
Step-by-step explanation:
