1/2 *(a+b)-(a-b)²
a=18, b=14
1/2 *(18+14)-(18-14)²=1/2 *(18+14)-(18-14)²= 1/2*32-4²=16-16=0
answer D
answer B
2 factors have 2 terms: (x+4) and (y+4)
<h3>Given</h3>
- C(t) = 40 cm + t·(2/5 cm/s) . . . circumference of a circle vs time
<h3>Find</h3>
- dr/dt for radius r
- r at t=4 seconds
<h3>Solution</h3>
The circumference and radius of a circle are related by
... C = 2πr
so the radius in terms of circumference is
... r = C/(2π)
... r(t) = (40 +0.4t)/(2π) = (1/π)(20 cm + 0.2t cm/s)
Then dr/dt is
... dr/dt = 0.2/π cm/s
And the radius at t=4 s is
... r(4) = (1/π)(20 + 0.2·4) cm
... r(4) = 20.8/π cm
Answer:
b. 2.333
Step-by-step explanation:
Test if the mean transaction time exceeds 60 seconds.
At the null hypothesis, we test if the mean transaction time is of 60 seconds, that is:
At the alternate hypothesis, we test if it exceeds, that is:
The test statistic is:
In which X is the sample mean, 
is the value tested at the null hypothesis, s is the standard deviation of the sample and n is the size of the sample.
60 is tested at the null hypothesis:
This means that 
A sample of 16 ATM transactions shows a mean transaction time of 67 seconds with a standard deviation of 12 seconds.
This means that 
Value of the test statistic:
Thus, the correct answer is given by option b.
Answer:
2.) undefined slope 3.) zero slope (i'm not sure what 1 and 4 are, sorry!)
Step-by-step explanation:
undefined slope has the same x-coordinate and the denominator becomes 0. it also is a vertical line. for a zero slope, it has the same y-coordinate and the numerator is 0. this is a horizontal line. *this is my first response so if i am wrong, that is embarrassing*
#3. For each hour worked, the employee makes $15/hour. This is true for every hour he works, so if he works for 4 hours he will make $60.
#4. For every second, the hot air balloon increases height by 5 feet.
#5. X&Y are proportional because for every hour, 5 feet are gained. Thus, after 7 hours, 35 feet are gained.
Thats all i have time to do right now. Good luck :)
