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1 year ago

15

The law of cosines is a2+b2-2abcosC=c2 find the value of 2abcosC

2 answers:

quester [9]1 year ago

7 0

Isolating 2abCos(c) on one side of the equation and using the given values of a, b and c we can find the answer to this question as shown below:

$a^{2} + b^{2} -2ab*cos(C)=c^{2} \\ \\ 
2ab *cos(C)= a^{2} + b^{2} - c^{2} \\ \\ 
2ab *cos(C)=2^{2} + 2^{2}- 1^{2} \\ \\ 
2ab*cos(C) = 7$

Westkost [7]1 year ago

4 0

2ab * cos (C)= 7

hope this helps you

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Find the length of side AB<br> Give answer to 3 significant figures

Rina8888 [55]

Answer:

AB = 8.857 cm

Step-by-step explanation:

Here, we are given a <em>right angle</em> $\triangle ABC$ in which we have the following things:

$\angle A = 90 ^\circ\\\angle C = 41 ^\circ\\\text{Side }BC = 13.5 cm$

Side <em>BC </em>is the hypotenuse here.

We have to find the side <em>AB</em>.

Trigonometric functions can be helpful to find the value of Side AB here.

Calculating $\angle B$ :

Sum of all the angles in $\triangle ABC$ is $180^\circ$ .

$\Rightarrow \angle A + \angle B + \angle C = 180^\circ\\\Rightarrow 90^\circ + \angle B + 41^\circ = 180^\circ\\\Rightarrow \angle B = 49^\circ$

We know that <em>cosine </em>of an angle is:

$cos \theta = \dfrac{\text{Base}}{\text{Hypotenuse}}\\\Rightarrow cos B = \dfrac{AB}{BC}\\\Rightarrow cos 49^\circ = \dfrac{AB}{13.5}\\\Rightarrow AB = 13.5 \times 0.656\\\Rightarrow AB = 8.857 cm$

So, side AB = 8.857 cm .

6 0

1 year ago

Determine the volume of the solid that lies between planes perpendicular to the x-axis at x=0 and x=4. The cross sections perpen

OverLord2011 [107]

Answer:

Volume = 16 unit^3

Step-by-step explanation:

Given:

- Solid lies between planes x = 0 and x = 4.

- The diagonals rum from curves y = sqrt(x) to y = -sqrt(x)

Find:

Determine the Volume bounded.

Solution:

- First we will find the projected area of the solid on the x = 0 plane.

A(x) = 0.5*(diagonal)^2

- Since the diagonal run from y = sqrt(x) to y = -sqrt(x). We have,

A(x) = 0.5*(sqrt(x) + sqrt(x) )^2

A(x) = 0.5*(4x) = 2x

- Using the Area we will integrate int the direction of x from 0 to 4 too get the volume of the solid:

V = integral(A(x)).dx

V = integral(2*x).dx

V = x^2

- Evaluate limits 0 < x < 4:

V= 16 - 0 = 16 unit^3

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1 year ago

The Atlantic bluefin tuna is the largest and most endangered of the tuna species. They are found throughout the North Atlantic O

Maksim231197 [3]

Answer:

Please see attachment

Step-by-step explanation:

Please see attachment

3 0

2 years ago

Hilda adds 5 to a number, then multiplies the sum by negative 2. The result is 6. Write an equation to find the number, x.

adell [148]

The equation would be x+5*-2=6.

The result of that equation would be x=16

7 0

2 years ago

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Graph the line y = kx +1 if it is known that the point M belongs to it: M(1,3)

tigry1 [53]

Answer:

$M(x,y) = (1,3)$ belongs to the line $y = 2\cdot x +1$ . Please see attachment below to know the graph of the line.

Step-by-step explanation:

From Analytical Geometry we know that a line is represented by this formula:

$y=k\cdot x + b$

Where:

$x$ - Independent variable, dimensionless.

$y$ - Dependent variable, dimensionless.

$k$ - Slope, dimensionless.

$b$ - y-Intercept, dimensionless.

If we know that $b = 1$ , $x = 1$ and $y = 3$ , then we clear slope and solve the resulting expression:

$k = \frac{y-b}{x}$

$k = \frac{3-1}{1}$

$k = 2$

Then, we conclude that point $M(x,y) = (1,3)$ belongs to the line $y = 2\cdot x +1$ , whose graph is presented below.

3 0

1 year ago