Answer:
a) $3480
b) $4036.8
Step-by-step explanation:
The compound interest formula is given by:

Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per year and t is the time in years for which the money is invested or borrowed.
Suppose that $3000 is placed in an account that pays 16% interest compounded each year.
This means, respectively, that 
So



(a) Find the amount in the account at the end of 1 year.
This is A(1).


(b) Find the amount in the account at the end of 2 years.
This is A(2).

a. Given that y = f(x) and f(0) = -2, by the fundamental theorem of calculus we have

Evaluate the integral to solve for y :



Use the other known value, f(2) = 18, to solve for k :

Then the curve C has equation

b. Any tangent to the curve C at a point (a, f(a)) has slope equal to the derivative of y at that point:

The slope of the given tangent line
is 1. Solve for a :

so we know there exists a tangent to C with slope 1. When x = -1/3, we have y = f(-1/3) = -67/27; when x = -1, we have y = f(-1) = -3. This means the tangent line must meet C at either (-1/3, -67/27) or (-1, -3).
Decide which of these points is correct:

So, the point of contact between the tangent line and C is (-1, -3).
Given:
Let P= profit
let n= no. of tacos sold per day
Sol'n:
P= 3.25n-210
the profit needs to be positive, thus
3.25n>210
n>210/3.25
n> 64.615
they can only sell whole tacos, therefore they must sell at least 65 tacos to make a profit and that profit is:
P=3.25n-210
P=3.25*65 - 210
P= 211.25 -210
P= 1.25
$1.25 profit
You can use cross product to slove this equation.
Here look at this for my answer...