Answer:
b
Step-by-step explanation:
Not easy:
- 4 < x^4 + 4x^2 ---> 0 < x^4+4x^2+4 = (x^2+2)^2, so it is always positive. Always satisfied. Curious ...
Now the other one:
x^4+4x^2<21 --> x^4+4x^2-21 < 0 --> (x^2+2)^2 - 25 < 0
(x^2+2)^2<25 ->>> x^2+2 < 5 ---> x^2 <3,
So -sqrt(3)<x<sqrt(3) is the answer! Brainliest?
Not sure why such an old question is showing up on my feed...
Anyway, let

and

. Then we want to find the exact value of

.
Use the angle difference identity:

and right away we find

. By the Pythagorean theorem, we also find

. (Actually, this could potentially be negative, but let's assume all angles are in the first quadrant for convenience.)
Meanwhile, if

, then (by Pythagorean theorem)

, so

. And from this,

.
So,
<span>The limousine will cost $240.
$180 for the first three hours, plus 30 for each hour after. They need two extra hours.
So, 180+30(2)=240.
They also want to leave a $20 dollar tip.
So, 240+20=260
That is $260 dollars they need to pay altogether.
Divide that number by the number of students and you'll get how much they each must pay.
260/8=32.50
$32.50 each.
♦Brainliest please♦
</span>
Answer:
It decreases.
Step-by-step explanation:
10 / d
Lets say that it was 10 / 40, which is 10 divided by 40, 0.25.
Now, it has increased to twice the amount of that.
1 / 80, 10 divided by 80, which is 0.125
So, it decreases.