Which of the following statements are true of the graph of the function f(x) = (x+5)(x-3)

1) Let f(x)=6x+6/x. Find the open intervals on which f is increasing (decreasing). Then determine the x-coordinates of all relat

brilliants [131]

Answer:

1) increasing on (-∞,-1] ∪ [1,∞), decreasing on [-1,0) ∪ (0,1]

$x = -1$ is local maximum, $x = 1$ is local minimum

2) increasing on [1,∞), decreasing on (-∞,0) ∪ (0,1]

$x = 1$ is absolute minimum

3) increasing on (-∞,0] ∪ [8,∞), decreasing on [0,4) ∪ (4,8]

$x = 0$ is local maximum, $x = 8$ is local minimum

4) increasing on [2,∞), decreasing on (-∞,2]

$x = 2$ is absolute minimum

5) increasing on the interval (0,4/9], decreasing on the interval [4/9,∞)

$x = 0$ is local minimum, $x = 4/9$ is absolute maximum

Step-by-step explanation:

To find minima and maxima the of the function, we must take the derivative and equalize it to zero to find the roots.

1) $f(x) = 6x + 6/x$

$f\prime(x) = 6 - 6/x^2 = 0$ and $x \neq 0$

So, the roots are $x = -1$ and $x = 1$

The function is increasing on the interval (-∞,-1] ∪ [1,∞)

The function is decreasing on the interval [-1,0) ∪ (0,1]

$x = -1$ is local maximum, $x = 1$ is local minimum.

2) $f(x)=6-4/x+2/x^2$

$f\prime(x)=4/x^2-4/x^3=0$ and $x \neq 0$

So the root is $x = 1$

The function is increasing on the interval [1,∞)

The function is decreasing on the interval (-∞,0) ∪ (0,1]

$x = 1$ is absolute minimum.

3) $f(x) = 8x^2/(x-4)$

$f\prime(x) = (8x^2-64x)/(x-4)^2=0$ and $x \neq 4$

So the roots are $x = 0$ and $x = 8$

The function is increasing on the interval (-∞,0] ∪ [8,∞)

The function is decreasing on the interval [0,4) ∪ (4,8]

$x = 0$ is local maximum, $x = 8$ is local minimum.

4) $f(x)=6(x-2)^{2/3} +4=0$

$f\prime(x) = 4/(x-2)^{1/3}$ has no solution and $x = 2$ is crtitical point.

The function is increasing on the interval [2,∞)

The function is decreasing on the interval (-∞,2]

$x = 2$ is absolute minimum.

5) $f(x)=8\sqrt x - 6x$ for $x>0$

$f\prime(x) = (4/\sqrt x)-6 = 0$

So the root is $x = 4/9$

The function is increasing on the interval (0,4/9]

The function is decreasing on the interval [4/9,∞)

$x = 0$ is local minimum, $x = 4/9$ is absolute maximum.

5 0

3 years ago

X+7≥18 The solution is ??

frozen [14]

Answer:

$x \geq 11$

Step-by-step explanation:

$x+7 \geq 18$

$x \geq 18-7$

$x \geq 11$

5 0

3 years ago

Read 2 more answers

Find the scale factor A. 3.5 B. 3/5 C. 35

Serhud [2]

Answer:

3.5

Step-by-step explanation:

35/10 = 3.5

4 0

3 years ago

Complete the sentence. 7 is 35% of _________.

Sonbull [250]

Okay, pretend the number equals X,
so x is 35%, and that would equal 7, so then
x is still 35/100 = 7
x = 7 which is 100/35
x = 700/35
x = 20
then you get the number = 20
I hope this was helpful, and good luck! :P

7 0

3 years ago

Read 2 more answers

The number of books borrowed from a library each week follows a normal distribution. When a sample is taken for several weeks, t

Marat540 [252]

$\mathbb P(X>250)=\mathbb P\left(\dfrac{X-190}{30}>\dfrac{250-190}{30}\right)=\mathbb P(Z>2)\approx0.0228$

Or, if you're familiar with the empirical rule and the basic properties of the normal distribution, you can use the fact that approximately $95/%$ of the distribution lies within two standard deviations of the mean, or

$\mathbb P(|Z|$

which means about $5\%$ of the distribution lies outside this interval, or

$\mathbb P((-22))\approx0.05$

Because the distribution is symmetric, you have

$\mathbb P(-22)$
$\implies \mathbb P((-22))=\mathbb P(-22)=2\mathbb P(Z>2)\approx0.05$
$\implies \mathbb P(Z>2)\approx 0.025$

8 0

3 years ago

Read 2 more answers