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2 years ago

What is the value of cosine (StartFraction 4 pi Over 3 EndFraction)? cos(4pi/3)

Mathematics

2 answers:

Dominik [7]2 years ago

8 0

The answer is 1/2.....

marin [14]2 years ago

3 0

Answer:

-square root 1/2 . It is a no c. if the answer is correct plz thank

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Draw a rectangular fraction model to explain your thinking. Then, write a multiplication sentence. A. 2 3 of = 3 5

myrzilka [38]

Answer:

$\frac{2}{3}\ of\ \frac{3}{5} = \frac{2}{5}$

Step-by-step explanation:

Given

$\frac{2}{3}\ of\ \frac{3}{5}$

Solving (a): Multiplication sentence

$\frac{2}{3}\ of\ \frac{3}{5}$

Rewrite of as *

$\frac{2}{3}\ of\ \frac{3}{5} = \frac{2}{3}\ *\ \frac{3}{5}$

Solve

$\frac{2}{3}\ of\ \frac{3}{5} = \frac{2}{5}$

Hence, the multiplication sentence is:

$\frac{2}{3}\ of\ \frac{3}{5} = \frac{2}{5}$

Solving (b): Rectangular fraction model

In (a) above, the result is 2/5

The fraction model will be represented as thus:

Draw a rectangle
Partition in to 5 equal parts (5 represents the denominator)
Shade 2 of the 5 partitions (2 represents the numerator)

<em>See attachment for model</em>

5 0

2 years ago

Prove algebraically that r = 10/2+2sinTheta is a parabola

Xelga [282]

Answer:

$y = - \frac{ 1 }{10} {x}^{2} + \frac{5}{2}$

Step-by-step explanation:

We want to prove algebraically that:

$r = \frac{10}{2 + 2 \sin \theta}$

is a parabola.

We use the relations

${r}^{2} = {x}^{2} + {y}^{2}$

and

$y = r \sin \theta$

Before we substitute, let us rewrite the equation to get:

$r(2 + 2 \sin \theta) = 10$

$r(1+ \sin \theta) = 5$

Expand :

$r+ r\sin \theta= 5$

We now substitute to get:

$\sqrt{ {x}^{2} + {y}^{2} } + y = 5$

This means that:

$\sqrt{ {x}^{2} + {y}^{2} }=5 - y$

Square:

${x}^{2} + {y}^{2} =(5 - y)^{2}$

Expand:

${x}^{2} + {y}^{2} =25 - 10y + {y}^{2}$

${x}^{2} =25 - 10y$

${x}^{2} - 25 = - 10y$

$y = - \frac{ {x}^{2} }{10} + \frac{5}{2}$

This is a parabola (0,2.5) and turns upside down.

4 0

3 years ago

There are 300 students. for every 8 are boys, and for every seven are girls. how many boys?

katen-ka-za [31]

8+7=15
300/15=20
8 x 20 =160 Boys
7 x 20 = 140 girls

140 + 160 = 300

Hope this helps!

4 0

3 years ago

What is the length of the apothem of a regular hexagon with 10-cm sides?

vodka [1.7K]

Answer:

The length of apothem of given hexagon is 8.66 cm

Step-by-step explanation:

Apothem of a polygon is given by:

$apothem = \frac{s}{2\ tan\ (\frac{180}{n})}$

Here

s is length of side

tan is trigonometric function

and n denotes number of sides

Given that the polygon is a hexagon

$s = 10cm\\n = 6$

Putting the values in the formula

$apothem = \frac{10}{2\ tan\ (\frac{180}{6})}\\= \frac{10}{2\ tan\ 30}\\=\frac{10}{2 * 0.5773}\\=\frac{10}{1.1546}\\=8.6610\\Rounding\ off\ to\ nearest\ hundredth\\= 8.66\ cm$

Hence,

The length of apothem of given hexagon is 8.66 cm

6 0

3 years ago

Someone help me pleaseeeeee

Simora [160]

Answer:

option B

Step-by-step explanation:

Top right graph

4 0

3 years ago

Read 2 more answers