Answer:
What do you need help with?
Answer:
x<3
Step-by-step explanation:
4x-1<11
4x<11+1
4x<12
divide by 4 each side
x<3

Substitute this into the parabolic equation,

We're told the line
intersects
twice, which means the quadratic above has two distinct real solutions. Its discriminant must then be positive, so we know

We can tell from the quadratic equation that
has its vertex at the point (3, 6). Also, note that

and

so the furthest to the right that
extends is the point (5, 2). The line
passes through this point for
. For any value of
, the line
passes through
either only once, or not at all.
So
; in set notation,

Answer:
405
Step-by-step explanation:
To find sample size, use the following equation, where n = sample size, za/2 = the critical value, p = probability of success, q = probability of failure, and E = margin of error.

The values that are given are p = 0.84 and E = 0.03.
You can solve for the critical value which is equal to the z-score of (1 - confidence level)/2. Use the calculator function of invNorm to find the z-score. The value will given with a negative sign, but you can ignore that.
(1 - 0.9) = 0.1/2 = 0.05
invNorm(0.05, 0, 1) = 1.645
You can also solve for q which is 1 - p. For this problem q = 1 - 0.84 = 0.16
Plug the values into the equation and solve for n.

Round up to the next number, giving you 405.