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1 year ago

if cos a = 1/3 then the positive value of tan 1/2a is? i did radical 2/3 over 4/3, but im not sure what to do now.

1 answer:

6 0

Hello,

$tg( \frac{a}{2} )=\pm \sqrt{ \dfrac{1-cos(a)}{1+cos(a)} } \\
=\pm \sqrt{ \dfrac{ \dfrac{2}{3} }{ \dfrac{4}{3} } } =\pm \sqrt{ \dfrac{1}{2} } =\pm \dfrac{ \sqrt{2} }{2} \\

+\ if\ \dfrac{a}{2}\ in\ 1\ quadrant\ (or \ 3)}\\

-\ if\ \dfrac{a}{2}\ in\ 2\ quadrant\ (or \ 4)}\\
$

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Which is more economical: purchasing the economy size of a detergent at 7 kilograms for $7.15 or purchasing the regular size a

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2 years ago

Helen’s house is located on a rectangular lot that is 1 1/8 miles by 9/10 mile.Estimate the distance around the lot

RUDIKE [14]

Answer:

The distance around the lot is 4.05 miles .

Step-by-step explanation:

Formula

$Perimeter\ of\ rectangle = 2 (Length + Breadth)$

As given

$Helen’s\ house\ is\ located\ on\ a\ rectangular\ lot\ that\ is\ 1 \frac{1}{8}\ miles\ by\ \frac{9}{10}\ mile.$

i.e

$Helen’s\ house\ is\ located\ on\ a\ rectangular\ lot\ that\ is\ \frac{9}{8}\ miles\ by\ \frac{9}{10}\ mile.$

Here

$Length = \frac{9}{8}\ miles$

$Breadth = \frac{9}{10}\ miles$

Put in the formula

$Perimeter\ of\ rectangle = 2(\frac{9}{8}+\frac{9}{10})$

L.C.M of (8,10) = 40

$Perimeter\ of\ rectangle = \frac{2\times (9\times 5+9\times 4)}{40}$

$Perimeter\ of\ rectangle = \frac{2\times (45+36)}{40}$

$Perimeter\ of\ rectangle = \frac{2\times 81}{40}$

$Perimeter\ of\ rectangle = \frac{81}{20}$

Perimeter of rectangle = 4.05 miles

Therefore the distance around the lot is 4.05 miles .

6 0

2 years ago

Read 3 more answers

Find a linear equation to model this real-world application:

SSSSS [86.1K]

The linear equation to model the company's monthly expenses is y = 2.5x + 3650

<em><u>Solution:</u></em>

Let "x" be the units produced in a month

It costs ABC electronics company $2.50 per unit to produce a part used in a popular brand of desktop computers.

Cost per unit = $ 2.50

The company has monthly operating expenses of $350 for utilities and $3300 for salaries

We have to write the linear equation

The linear equation to model the company's monthly expenses in the form of:

y = mx + b

Cost per unit = $ 2.50

Monthly Expenses = $ 350 for utilities and $ 3300 for salaries

Let "y" be the total monthly expenses per month

Then,

Total expenses = Cost per unit(number of units) + Monthly Expenses

$y = 2.50(x) + 350 + 3300\\\\y = 2.5x + 3650$

Thus the linear equation to model the company's monthly expenses is y = 2.5x + 3650

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2 years ago

James has a desk job and would like to become more fit, so he purchases a tread walker and a standing desk which will allow him

Hitman42 [59]

Answer:

answer is

$-0.245 \pm2.160(0.205)$

Step-by-step explanation:

After working this way for 6 months he takes a simple random sample of 15 days. He records how long he walked that day (in hours) as recorded by his fitness watch as well as his billable hours for that day as recorded by a work app on his computer.

Slope is -0.245

Sample size n = 15

Standard error is 0.205

Confidence level 95

Sognificance level is (100 - 95)% = 0.05

Degree of freedom is n -2 = 15 -2 = 13

Critical Value =2.16 = [using excel = TINV (0.05, 13)]

Marginal Error = Critical Value * standard error

= 2.16 * 0.205

= 0.4428

$-0.245 \pm2.160(0.205)$

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2 years ago

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