Answer:
$3100 is invested at 9%
$4900 is invested at 11%
Step-by-step explanation:
Let's take "x" be the amount invested at 9%.
(x + 1800) is invested in another account at 11%.
The interest amount earned by the two accounts is $818.
Here we can use the simple interest formula and find the amount invested in each account.
Simple interest (I) = , where P- is the principal , N is the number of years and R is the interest rate.
Simple interest =
0.09x + 0.11(x+1800) = 818
Now we have to simplify and find the value of x .
Use the distributive property and simplify the second term.
0.09x + 0.11x + 198 = 818
0.2x + 198 = 818
0.2x =818 - 198
0.2x = 620
x = 620/0.2
x = 3100.
So $3100 is invested at 9%
x + 1800 = 3100 + 1800
= $4900
$4900 is invested at 11%
Hope this helped.
A circle is a geometric object that has symmetry about the vertical and horizontal lines through its center. When the circle is a unit circle (of radius 1) centered on the origin of the x-y plane, points in the first quadrant can be reflected across the x- or y- axes (or both) to give points in the other quadrants.
That is, if the terminal ray of an angle intersects the unit circle in the first quadrant, the point of intersection reflected across the y-axis will give an angle whose measure is the original angle subtracted from the measure of a half-circle. Since the measure of a half-circle is π radians, the reflection of the angle π/6 radians will be the angle π-π/6 = 5π/6 radians.
Reflecting 1st-quadrant angles across the origin into the third quadrant adds π radians to their measure. Reflecting them across the x-axis into the 4th quadrant gives an angle whose measure is 2π radians minus the measure of the original angle.
4,000 +000 +00 + 0 is stander form for four thousand
The function for the height is

f(0) = 5 cos(0) + 7 = 5 + 7 = 12 (verified)
The period is T = 12 hours.
After 4 hours (t = 4), the height is

A graph of f(t) confirms the answer.
Answer: 4.5 ft