All categories

2 years ago

F(x)=x^-2x+4 find f(-1)

Mathematics

1 answer:

otez555 [7]2 years ago

7 0

Hello,

$f(x)=x^{-2}+4\\

f(-1)=(-1)^{-2}+4= \dfrac{1}{(-1)^2} +4=1+4=5\\
$

You might be interested in

Nina works at an hourly rate of $12.25 per hour and worked 46 hours last week. She earns overtime for hours exceeding 40 hours.

Alenkinab [10]

Answer:

$600.25

Step-by-step explanation:

12.25 per week

46hrs last week

40+ = overtime

Overtime = t*1.5

------------------------------

46-40= 6hrs of overtime

40*12.25= 490 - this is her money for working 40hrs.

To figure out the money amount of overtime pay--- 12.25*1.5= 18.375 (18.38)

add now

<em>110.25+490= $600.25</em>

=) ~i hope i helped~ =)

6 0

2 years ago

A population of bees is decreasing. The population in a particular region this year is 1,250. After 1 year, it is estimated tha

8_murik_8 [283]

To model this situation, we are going to use the decay formula: $A=Pe^{rt}$
where
$A$ is the final pupolation
$P$ is the initial population
$e$ is the Euler's constant
$r$ is the decay rate
$t$ is the time in years

A. We know for our problem that the initial population is 1,250, so $P=1250$ ; we also know that after a year the population is 1000, so $A=1000$ and $t=1$ . Lets replace those values in our formula to find $r$ :
$A=Pe^{rt}$
$1000=1250e^{r}$
$e^{r}= \frac{1000}{1250}$
$e^{r}= \frac{4}{5}$
$ln(e^{r})=ln( \frac{4}{5} )$
$r=ln( \frac{4}{5} )$
$r=-02231$

Now that we have $r$ , we can write a function to model this scenario:
$A(t)=1250e^{-0.2231t}$ .

B. Here we are going to use a graphing utility to graph the function we derived in the previous point. Please check the attached image.

C.
- The function is decreasing
- The function doe snot have a x-intercept
- The function has a y-intercept at (0,1250)
- Since the function is decaying, it will have a maximum at t=0:
$A(0)=1250e^{(-0.2231)(0)$
$A_{0}=1250e^{0}$
$A_{0}=1250$
- Over the interval [0,10], the function will have a minimum at t=10:
$A(10)=1250e^{(-0.2231)(10)$
$A_{10}=134.28$

D. To find the rate of change of the function over the interval [0,10], we are going to use the formula: $m= \frac{A(0)-A(10)}{10-0}$
where
$m$ is the rate of change
$A(10)$ is the function evaluated at 10
$A(0)$ is the function evaluated at 0
We know from previous calculations that $A(10)=134.28$ and $A(0)=1250$ , so lets replace those values in our formula to find $m$ :
$m= \frac{134.28-1250}{10-0}$
$m= \frac{-1115.72}{10}$
$m=-111.572$
We can conclude that the rate of change of the function over the interval [0,10] is -111.572.