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liberstina [14]
3 years ago
12

Sec square 75 degree + cot square 15 degree ​

Mathematics
2 answers:
igor_vitrenko [27]3 years ago
7 0

Answer:

Step-by-step explanation:

but

You work for the final answer.

Lelechka [254]3 years ago
3 0

Answer:

(6 +√3) / (2 - √3).

Step-by-step explanation:

sec 75 = 1/cos 75

cos 75 = cos45cos30 - sin45sin30

= 1/√2 * √3/2 - 1/√2 * 1/2

= (√3 - 1 )/ 2√2.

cos^2 75

=  (√3 - 1 )^2 / (2√2)^2

= (3 - 2√3 + 1 / 8

= (2 - √3) / 4

So sec^2 75  = 4 / (2 - √3)

tan 15 =  tan (45 - tan 30)

= tan 45 - tan 30 / 1 + tan45 tan30

= ( 1 - √3/3 ) / (1 + 1 * √3 / 3)

= (3 - √3) / (3 + √3)

tan^2 15 =  (9 - 6√3 + 3) / (9 + 6√3 + 3)

= 12 - 6√3  (12 + 6√3)

=  2 - √3 / 2 + √3

So cot^2 15 = (2 + √3) / (2 - √3)

Finally sec^2 75 + cot^2 15

= 4 / (2 - √3) +  (2 + √3) / (2 - √3)

= (6 +√3) / (2 - √3)

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A person has 20 coins consisting of dimes and quarters if the total amount of money is $4.70 how many quarters are there
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6 0
3 years ago
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Hatshy [7]

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3 0
2 years ago
According to Thomson Financial, last year the majority of companies reporting profits had beaten estimates. A sample of 162 comp
vova2212 [387]

Answer:

0.1790

0.0738 , 0.5800, 0.7040

354

Step-by-step explanation:

a. Given:  

n = 162

x = 29

c = 95%

The point estimate of the population proportion is the sample proportion. The sample proportion is the number of successes divided by the sample size:  

p =  x/n

  = 29/162

  = 0.1790

b. Given:  

n=162

x = 110

c = 95%

The point estimate of the population proportion is the sample proportion. The sample proportion is the number of successes divided by the sample size:  

p =  x/n

  =110/162

  =0.6790

For confidence level 1 –\alpha = 0.95, determine z_\alpha/2 = z_0.025 using table 1 (look up 0.025 in the table, the z-score is then the found z-score with opposite sign):  

z_\alpha/2 = 1.96  

The margin of error is then:

E =  z_\alpha/2*√p(1-p)/n =1.96* √0.6790(1-0.6790)/162 =0.0738

The boundaries of the confidence interval are then:  

p-z_\alpha/2*√p(1-p)/n = 0.6790-1.645√ 0.6790(1- 0.6790)/162 = 0.5800

p+z_\alpha/2*√p(1-p)/n = 0.6790+1.645√ 0.6790(1- 0.6790)/162 = 0.7040

c. Given:  

n = 162

x = 110

c = 95%

The point estimate of the population proportion is the sample proportion. The sample proportion is the number of successes divided by the sample size:  

p =x/n

  =0.6790

Formula sample size:

p known: n = [z_\alpha/2 ]^2*pq/E^2

                   = [z_\alpha/2 ]^2*p(1-p)/E^2

                n = [z_\alpha/2 ]^2*0.25/E^2

For confidence level 1 –\alpha= 0.95, determine z_\alpha/2 = z_o.025 using table 1 (look up 0.025 in the table, the z-score is then the found z-score with opposite sign):  

z_\alpha/2  = 1.96

p is known, then the sample size is (round up!):

n =[z_\alpha/2 ]^2*p(1-p)/E^2

  = 354

8 0
3 years ago
PLEASE HELP!!! ANYONE???
Nadusha1986 [10]
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