38.=721.8 it's really just a matter of multiplication. I only have he answer for this one but, y'know, work and whatnot. If you would multiply 3 by 3 than wou would do the same for this problem
<h3>
Answer:</h3>
- left picture (bottom expression): -cot(x)
- right picture (top expression): tan(x)
<h3>
Step-by-step explanation:</h3>
A graphing calculator can show you a graph of each expression, which you can compare to the offered choices.
_____
You can make use of the relations ...
... sin(a)+sin(b) = 2sin((a+b)/2)cos((a-b)/2)
... cos(a)+cos(b) = 2cos((a+b)/2)cos((a-b)/2)
... cos(a)-cos(b) = -2sin((a+b)/2)sin((a-b)/2)
Then you have ...

and ...

Answer:
a) 
b) 
c)


Step-by-step explanation:
a)
We know that Revenue is our total income and cost is our total cost. Thus, profit is what's left after cost is subtracted from Income (revenue). Thus, we can say:
P(x) = R(x) - C(x)
Finding Profit Function (P(x)):

This is the profit function.
b)
The marginal profit is the profit earned when ONE ADDITIONAL UNIT of the product is sold. This is basically the rate of change of profit per unit. We find this by finding the DERIVATIVE of the Profit Function.
Remember the power rule for differentiation shown below:

Now, we differentiate the profit function to get the marginal profit function (P'):

This is the marginal profit function , P'.
c)
We need to find P'(4000) and P'(9500). So we basically put "4000" and "9500" in the marginal profit function's "x". The value is shown below:

and

Answer:
D. The system is in echelon form.
Step-by-step explanation:
Check attachment