Answer:
after 10 seconds the charge is 1.624
Step-by-step explanation:
I think your question missed key information, allow me to add in and hope it will fit the orginal one.
The electrical charge on a metal plate is given by the function below, where t is the time in seconds. What is the charge after 10 seconds?
C (t) = 12
My answer:
Given the information:
C (t) = 12
when t =10 we have:
C (10) = 12
<=> C (10) = 12
<=> C (10) = 12
<=> C (10) = 12 * 0.1353
<=> C (10) = 1.624
Hence, after 10 seconds the charge is 1.624
-π/2 < arctan(x) < π/2
So cos(π/2) < cos(arctan(x)) < cos(0)
0 < cos(arctan(x)) < 1
Answer: 220
<u>Step-by-step explanation:</u>
Children (x): $2
Teens (y): $3, 
Adults: (z): $5
Quantity: x + y + z = 570 ⇒ x + + z = 570 ⇒ 1.75x + z = 570
Cost: 2x + 3y + 5z = 1950 ⇒ 2x + 3
+ 5z = 1950 ⇒ 2x + 2.25x + 5z = 1950 ⇒ 4.25x + 5z = 1950
Qty: 1.75x + z = 570 → 5(1.75x + z = 570) → 8.75x + 5z = 2850
Cost: 4.25x + 5z = 1950 → -1(4.25x + 5z = 1950 → <u> -4.25x - 5z</u> = <u>-1950 </u>
4.50x = 900
x = 200
Teens (y):
y = 
= 
= 150
Quantity: x + y + z = 570
200 + 150 + z = 570
350 + z = 570
z = 220
