Answer:
18) 4 * 10 ^ -10
19) t ^ 9
Step-by-step explanation:
18. When multiplying in scientific notation, just multiply the regular numbers together and add the exponents for the tens.
So it'll be 40 * 10^-11
However, the beginning number should have the decimal right after the 4, not any place after (for example, it's 3.056, not 30.56 or 3056.)
To fix this, move the decimal place forward one space from 40. to 4.0, and add 1 to the -11 power.
So the answer is now 4 * 10^-10
19. When dividing exponents, if the base number is the same, you can divide. (Basically, you can not divide x^2 and y^3 because x and y aren't the same)
Since in this case it's t, you can divide.
Dividing exponents is simple: just subtract them.
14 - 5 = 9
so the answer is t ^ 9
B. Accuracy is if it's right or not. Precision is how many decimal places it goes out to. So it is precise but not accurate.
The answer in b next time make sure the picture is clear
a) You are told the function is quadratic, so you can write cost (c) in terms of speed (s) as
... c = k·s² + m·s + n
Filling in the given values gives three equations in k, m, and n.

Subtracting each equation from the one after gives

Subtracting the first of these equations from the second gives

Using the next previous equation, we can find m.

Then from the first equation
[tex]28=100\cdot 0.01+10\cdot (-1)+n\\\\n=37[tex]
There are a variety of other ways the equation can be found or the system of equations solved. Any way you do it, you should end with
... c = 0.01s² - s + 37
b) At 150 kph, the cost is predicted to be
... c = 0.01·150² -150 +37 = 112 . . . cents/km
c) The graph shows you need to maintain speed between 40 and 60 kph to keep cost at or below 13 cents/km.
d) The graph has a minimum at 12 cents per km. This model predicts it is not possible to spend only 10 cents per km.