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).
Answer:
Step-by-step explanation:
Both 115 and 145 mph are above the mean. Draw a normal curve and mark these speeds. 115 mph is 1 standard deviation above the mean; 130 would be 2 standard deviations above the mean; and 145 would be 3 s. d. above it.
We need to find the area under the standard normal curve between 115 and 145. This is equivalent to the area under the standard normal curve between z = 1 and z = 3.
I used my TI-83 Plus calculator's DISTR function "normalcdf(" to calculate this area: normalcdf(1, 3) = 0.1573.
The area between z = 1 and z = 3 is 0.1573. In other words, the percentage of serves that were between 115 and 145 mph was 15.73%.
Answer:
136° that's 90 plus 46.........
Answer:
thats right.
Step-by-step explanation:
the first place after the decimal is tenths, second, hundredths, third thousands, and so on
Answer:
See below
Step-by-step explanation:
we have f(x) = -(x-7) + 3
and we want to find f(4)
essentially, f(4) means that the input is 4 and to find the output we plug in the value of the input where ever x is and evaluate.
So for f(x) = -(x-7) + 3
To find f(4) we replace all x's with 4
f(4) = -(4-7) + 3
we now evaluate
==> subtract 7 from 4
f(4) = -(-3) + 3
==> apply two negative rule ( basically if there are two negative signs they cancel out and the number turn positive )
f(4) = 3 + 3
==> add 3 and 3
f(4) = 6
