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3 years ago

Which of the following is the product for (x+4)(x-2)?

Mathematics

1 answer:

larisa86 [58]3 years ago

6 0

Answer:

Step-by-step explanation:

X times x is x squared then x times - 2 is - 2x but 4 times x is 4x. So 4x plus - 2x is 2x. Then 4 times - 2 is - 8 put that all together you'll get x^+ 2+2x-8

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Help, and if you can give me a step by step explanation

Llana [10]

Answer:

the first option

Step-by-step explanation:

variability !

what does that word tell us ?

it means that there are more individuals differences.

you could also use "accuracy" as the opposite - we are aiming for the mean value ...

imagine some bow and arrow tournament.

who wins ?

the person with the highest accuracy across all the attempts (and that means the lowest variability in the results across all attempts relatively to the target center representing the predefined mean value).

now look at the graphic for neighborhood A.

and then for neighborhood B.

which one has the data points more clustered around the center (where the mean value is going to be) ? this one has lower variability than the one where the data points are having more than one cluster or are even all over the place.

remember, for the variability you have to add all the differences to the mean value. the smaller the differences to the mean value, the smaller the variability.

in neighborhood B almost all data points have a larger difference to the mean value.

so, the variability will be higher here.

5 0

2 years ago

Somebody help me please

posledela

130 degrees.

ADB = 90 degrees
BDT=40 Degrees

Therefore, TDS = ADB(90)+BDT(40)=130 degrees

8 0

3 years ago

A 140 kg camera is suspended by two wires over a 40 metre wide football field to get shots of the action from above. At one poin

Katen [24]

Answer:

Please red the answer below

Step-by-step explanation:

In order to determine the length of each cable you use the Newton second law for each component of the forces involved in the situation.

For the x component you have:

$T_1cos\theta_1-T_2cos\theta_2=0$ (1)

T1: tension of the first cable = 1500N

T2: tension of the second cable = 800N

θ1: angle between the horizontal and the first cable

θ2: angle between the horizontal and the first cable

For the y component you have:

$T_1sin\theta_1+T_2sin\theta_2-W=0$ (2)

W: weight of the camera = Mg = (140kg)(9.8m/s^2) = 1372N

You can squared both equations (1) and (2) and the sum the two equations:

$T_1^2cos^2\theta_1=T_2^2cos^2\theta_2\\\\T_1^2sin^2\theta_1=T_2^2sin^2\theta_2-2WT_2sin\theta_2+W^2$

Then, you sum the equations:

$T_1^2(cos^2\theta_1+sin^2\theta_1)=T_2^2(sin^2\theta_2+cos^2\theta_2)-2Wsin\theta_2+W^2$ (3)

Next, you use the following identity:

$sin^2\theta+cos^2\theta=1$

and you obtain in the equation (3):

$T_1^2=T_2^2-2WT_2sin\theta_2+W^2\\\\sin\theta_2=\frac{T_2^2-T_1^2+W^2}{2WT_2}=\frac{(800N)^2-(1500)^2+(1372N)^2}{2(800N)(1372N)}=0.066\\\\\theta_2=sin^{-1}0.066=27.23\°$

With this values you can calculate the value of the another angle, by using the equation (1):

$\theta_1=cos^{-1}(\frac{T_2cos(27.23\°)}{T_1})=cos^{-1}(\frac{(800N)(cos27.23\°)}{1500N})\\\\\theta_1=61.69\°$

Now, you can calculate the length of each cable by using the information about the width of the football field. You use the following trigonometric relation:

$l_1cos\theta_1=40-d\\\\l_2cos\theta_2=d\\\\$