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3 years ago

I am leaning pre-cal right now and I don't understand it. I did arctan (3/-5) but got it wrong, how do you do this?

Mathematics

1 answer:

Gemiola [76]3 years ago

7 0

9514 1404 393

Answer:

149.04°

Step-by-step explanation:

You must consider the signs of the components of the vector. The value -5+3i will be in the 2nd quadrant of the complex plane.

When you use the single-argument arctan function, it will tell you the angle is -30.96°, a 4th-quadrant angle. (arctan( ) is only capable of giving you 1st- or 4th-quadrant angles.)

You find the 2nd-quadrant angle by adding 180° to this value:

-30.96° +180° = 149.04° = arg(-5+3i)

The attachments show the calculation using a suitable calculator (1st) and a spreadsheet (2nd). The spreadsheet function ATAN2(x,y) gives the 4-quadrant angle in radians, considering the signs of the two arguments. Here, we converted it to degrees. The calculator can be set to either degrees or radians.

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PLEASE CAN SOMEONE ANSWER THIS!!!! DEADLINE SOON!!!

Verdich [7]

Hello There!

I believe that the relationships that can help you solve this problem are that the angle is Complementary and Supplementary. It is complementary because within the angle, there is an angle that is 90°. It is also supplementary because the angle itself is 180° making the angle supplementary.

I hope this helps!

8 0

3 years ago

If 89 babies are sampled at random from the hospital, what is the probability that the mean weight of the sample babies would di

cricket20 [7]

Answer:

0.6836

Step-by-step explanation:

(weight - mean weight) = 48

Variance, s² = 204,304

Sample size, n = 89

We need to obtain the Zscore :

Zscore = (X - mean) / standard Error

Zscore = (weight - mean weight ) / (s/√n)

s = √204304 = 452

The difference from the meanncoukdnbe either to the right or left :

Zscore = - 48 / (452/√89) OR 48 / (452/√89)

Zscore = - 48 / 47.911904 OR - 48 / 47.911904

Zscore = - 1.002 or 1.002

P(Z < - 1.002) = 0.1582 (using Z table)

P(Z < 1.002) = 0.8418

P(Z < 1.002) - P(Z < - 1.002)

0.8418 - 0.1582

= 0.6836

6 0

3 years ago

How many eighth size parts do you need to model 3/4

zzz [600]

Answer:

You need 6, 1/8 parts to make 3/4

Step-by-step explanation:

The answer is 6 because 1/8 multiplied by 6 is 6/8 and 6/8 simplified is 3/4

8 0

2 years ago

Read 2 more answers

Plz help me with this

AnnZ [28]

Answer: $\bold{A)\quad y=5sin\bigg(\dfrac{6}{5}x-\pi\bigg)-4}$

<u>Step-by-step explanation:</u>

The general form of a sin/cos function is: y = A sin/cos (Bx-C) + D where the period (P) = 2π ÷ B

In the given function, $B=\dfrac{6}{5}$ → $P=2\pi \cdot \dfrac{5}{6}=\dfrac{10\pi}{3}$

Half of that period is: $\dfrac{1}{2}\cdot \dfrac{10\pi}{3}=\large\boxed{\dfrac{5\pi}{3}}$

Calculate the period for each of the options to find a match:

$A)\quad B=\dfrac{6}{5}:\quad 2\pi \div \dfrac{6}{5}=2\pi \cdot \dfrac{5}{6}=\dfrac{5\pi}{3}\quad \leftarrow\text{THIS WORKS!}\\\\\\B)\quad B=\dfrac{6}{10}:\quad 2\pi \div \dfrac{6}{10}=2\pi \cdot \dfrac{10}{6}=\dfrac{10\pi}{3}\\\\\\C)\quad B=\dfrac{5}{6}:\quad 2\pi \div \dfrac{5}{6}=2\pi \cdot \dfrac{6}{5}=\dfrac{12\pi}{5}\\\\\\D)\quad B=\dfrac{3}{10}:\quad 2\pi \div \dfrac{3}{10}=2\pi \cdot \dfrac{10}{3}=\dfrac{20\pi}{3}$

7 0

3 years ago

Length of a rectangle is 5 cm longer than the width. Four squares are constructed outside the rectangle such that each of the sq

stiv31 [10]

Answer:

Step-by-step explanation:

Remark

This is one of those questions that can throw you. The problem is that do you include the original rectangle or not. The way it is written it sounds like you shouldn't

However if you don't the question gives you 2 complex answers. (answers with the sqrt( - 1) in them.

Solution

Let the width = x

Let the length = x + 5

Area of the rectangle: L * w = x * (x + 5)

Area of the smaller squares (there are 2)

Area = 2*s^2

x = s

Area = 2 * x^2

Area of the larger squares = 2 * (x+5)^2

Total Area

x*(x + 5) + 2x^2 + 2(x + 5)^2 = 120 Expand

x^2 + 5x + 2x^2 + 2(x^2 + 10x + 25) = 120 Remove the brackets

x^2 + 5x + 2x^2 + 2x^2 + 20x + 50 = 120 collect the like terms on the left

5x^2 + 25x + 50 = 120 Subtract 120 from both sides.

5x^2 + 25x - 70 = 0 Divide through by 5

x^2 + 5x - 14 = 0 Factor

(x + 7)(x - 2) = 0 x + 7 has no meaning

x - 2 = 0

x = 2

Perimeter

P = 2*w + 2*L

w = 2

L = 2 + 5

L = 7

P = 2*2 + 2 * 7

P = 4 + 14

P = 18

8 0

3 years ago