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2 years ago

Last question (arc length and area) thanks!!!

Mathematics

1 answer:

Lynna [10]2 years ago

7 0

Answer:

$m\angle ABC=60\textdegree$

Step-by-step explanation:

$m\angle ABC=360-90-90-m\angle AOC\\=180-120\\=60\textdegree$

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I really need help! This is last minute and its 1 am. I'm tired so I'm going to leave it to you guys to solve my problems and pr

Illusion [34]

Answer:

<h2><u>question 1</u></h2>

$n^{2} - 20n -96 = 0$

use product and sum method

product = -96

sum = -20

numbers needed = ( -24 , 4)

n - 24 = 0

n + 4 = 0

hence <u>n = 24 and n = -4 </u>

<u></u>

<h2><u>Question 2 </u></h2>

in the form $ax^{2} +bx +c = 0$

= $x^{2} +12x - 48$

make use of the formula :

$\frac{-b+-\sqrt{b^{2} -4ac} }{2a}$

replace values to make 2 equations :

1. $\frac{-12+\sqrt{12^{2} -4*1*-48} }{2*1}$ = 3.17

2. $\frac{-12-\sqrt{12^{2} -4*1*-48} }{2*1}$ = -15.2

hence <u>x = 3.17 and x = -15.2</u>

<u />

<h2><u>Question 3 </u></h2>

use product and sum method

product = 40

sum = -14

numbers needed = (-10 , -4)

x - 10 = 0

x - 4 = 0

hence<u> x = 10 and x = 4</u>

<u />

<h2><u>Question 4 </u></h2>

in the form $ax^{2} +bx +c = 0$

this becomes $5b^{2} -20b-18-7$

= $5b^{2} -20b-25$

can simplify by 5

= $b^{2} -4b-5 =0\\$

use product and sum method

product = -5

sum = -4

numbers needed (-5 , 1)

b-5 = 0

b + 1 = 0

hence <u>b = 5 and b = -1</u>

5 0

3 years ago

Read 2 more answers

Rice weighing 3¾ pounds was divided equally and placed in 4 containers. How many ounces of rice were in each?

grigory [225]

Answer:

15/16

Step-by-step explanation:

3 3/4 divided by 4 = 15/16

4 0

3 years ago

If sin(A+B)=1/2 & sin(A-B)=1/3 find sin(2A)

timofeeve [1]

Answer:

sin(2A) = (2√2 + √3) / 6

Step-by-step explanation:

2A = (A+B) + (A−B)

sin(2A) = sin((A+B) + (A−B))

Angle sum formula:

sin(2A) = sin(A+B) cos(A−B) + sin(A−B) cos(A+B)

sin(2A) = 1/2 cos(A−B) + 1/3 cos(A+B)

Pythagorean identity:

sin(2A) = 1/2 √[1 − sin²(A−B)] + 1/3 √[1 − sin²(A+B)]

sin(2A) = 1/2 √(1 − 1/9) + 1/3 √(1 − 1/4)

sin(2A) = 1/2 √(8/9) + 1/3 √(3/4)

sin(2A) = 1/3 √2 + 1/6 √3

sin(2A) = (2√2 + √3) / 6

6 0

3 years ago

Look at the screenshot, please. (no links)

elena-s [515]

Answer: 14

Step-by-step explanation: 18 x 14 = 252

3 0

3 years ago

Read 2 more answers

A researcher compares the effectiveness of two different instructional methods for teaching physiology. A sample of 178 students

xxTIMURxx [149]

Answer:

critical value = 1.645

The 90% confidence interval = ( -22.62, -17.58)

Step-by-step explanation:

Given that:

the sample size $n_1$ = 178

the sample size $n_2$ = 226

the sample mean $\overline x_1$ = 54.4

the sample mean $\overline x_2$ = 74.5

population standard deviation $\sigma_1$ = 18.58

population standard deviation $\sigma_2$ = 9.52

level of significance ∝ = 1 - 0.90 = 0.10

The critical value for $Z_{\alpha/2} = Z _{0.10/2} = Z_{0.005}$ is 1.645

For the construction of our confidence interval, we use 90% since that is used to find the critical value.

∴

The margin of error = $Z \times\sqrt{\dfrac{\sigma_1^2}{n_1} + \dfrac{\sigma_2^2}{n_2}}$

$1.645 \times\sqrt{\dfrac{18.58^2}{178} + \dfrac{9.52^2}{226}}$

$1.645 \times\sqrt{\dfrac{345.2164}{178} + \dfrac{90.6304}{226}}$

$1.645 \times\sqrt{2.34042}$

$\simeq$ 2.52

The lower limit = $( \overline x_1 - \overline x_2) - (M.O.E)$

= ( 54.4-74.5) - (2.52)

= -20.1 - 2.52

= -22.62

The upper limit = $( \overline x_1 - \overline x_2) + (M.O.E)$

= ( 54.4-74.5) + (2.52)

= -20.1 + 2.52

= -17.58

The 90% confidence interval = ( -22.62, -17.58)

6 0

3 years ago