Help please I really need to pass

Find the angle between V and W, Round your answer to one decimal place, if necessary V=-5i+2j W=-8i+2j A 17.8° B 353.9° C 3.9° D

LiRa [457]

Answer:

D. 7.8°

Step-by-step explanation:

There are many ways to work this problem. One is to subtract the angle of V from that of W:

∠V = arctan(2/-5) ≈ 158.20°

∠W = arctan(2/-8) ≈ 165.96°

Then ∠W -∠V = 165.96° -158.20° = 7.76° ≈ 7.8°

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Another is to divide W by V, since the quotient will have an angle that is the difference of their two angles.

(-8i +2j)/(-5i +2j) = (1/29)(44i +6j)

Then the angle of that is ...

arctan(6/44) ≈ 7.8°

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You can also divide the dot product by the product of the two magnitudes to find the cosine of the angle between the vectors.

(V•W)/(|V|·|W|) = 44/√(68·29) = cos(x)

x = arccos(0.990830168...) ≈ 7.8°

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A plot on graph paper will let you measure the angle with a protractor. You can obtain sufficient accuracy to choose between the offered answers.

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Your graphing calculator may have complex number functions that let you work directly with the angles of the vectors. (See second attachment. The calculator is in degrees mode.) Doing 2-dimensional vector calculations on a calculator may best be accomplished by treating them as complex numbers.

5 0

4 years ago

Consider a value to be significantly low if its z score less than or equal to minus−2 or consider a value to be significantly hi

katrin2010 [14]

Answer:

Test scores of 10.2 or lower are significantly low.

Test scores of 31.4 or higher are significantly high.

Step-by-step explanation:

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 20.8, \sigma = 5.3$

Identify the test scores that are significantly low or significantly high.

Significantly low

Z = -2 and lower.

So the significantly low scores are thoses values that are lower or equal than X when Z = -2. So

$Z = \frac{X - \mu}{\sigma}$

$-2 = \frac{X - 20.8}{5.3}$

$X - 20.8 = -2*5.3$

$X = 10.2$

Test scores of 10.2 or lower are significantly low.

Significantly high

Z = 2 and higher.

So the significantly high scores are thoses values that are higherr or equal than X when Z = 2. So

$Z = \frac{X - \mu}{\sigma}$

$2 = \frac{X - 20.8}{5.3}$

$X - 20.8 = 2*5.3$

$X = 31.4$

Test scores of 31.4 or higher are significantly high.

3 0

4 years ago

The circumference of a circle F is about 25 cm

lana [24]

THE AWNSER WILL BE 50 YOU TIMES IT BY 2 SO 2 TIMES 25 IS 50 IM IN COLLEGE PEPS I KNOW EVERYTHING

7 0

4 years ago

Write a quadratic function f whose zeros are 6 and 1

Ratling [72]

Answer:

x^2-7x+6

Step-by-step explanation:

(x-6)(x-1)

x^2-1x-6x+6

x^2-7x+6

4 0

3 years ago

Guys i’m begging someone help me please!!!!

IRISSAK [1]

Answer:

x= 35

Step-by-step explanation:

supposing we are finding x, we know that the line in the middle is the dimeter. so we know its a semicircle with an arc of 180 degrees. 180-110=70 divide that by two to get x which is 35.

4 0

3 years ago

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