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4 years ago

Please I really need help! Can you answer A and B and I will mark you as brainliest!

Mathematics

1 answer:

Georgia [21]4 years ago

3 0

a) The average arithmetic mean is calculated by adding all of the values and then dividing the sum by the total number of values.

$\frac{198+199(3)+200(2)+201(5)+202(2)}{13} =200.3$

Which is 200.3.

b) Assume that the new average mean is 201, then

$201 = \frac{198 + 199(3) + 200(2) + 201(5) + 202(2)+x}{14}$

Solve for x.

$2814= 2604x$

Divide by 2604 to solve for x.

$\frac{2814}{1604} = x = 1.75$

So the height of the new player is 175 cm.

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The area of the triangle whose side lengths are 7cm, 24cm and 25cm is ?

Sergio039 [100]

Answer: the area is 84 cm^2

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3 years ago

-2x=-2x+8 i need help asap step by step please

Blizzard [7]

Answer:

0=8

Step-by-step explanation:

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3 years ago

What is the mixed number for 4.8 in simplest form

ollegr [7]

The mixed number for 4.8 is 4 8/10

For simplest form, divide 8/10 by 2 to get 4/5

Your final answer would be 4 4/5

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4 years ago

Show that cos(3theta) = 4cos3(theta) − 3cos (theta).

Delvig [45]

Step-by-step explanation:

To prove:

$\cos 3\theta=3\cos^3 \theta-3\sin^2 \theta\cos \theta$

Identities used:

$\cos(A+B)=\cos A\cos B+\sin A\sin B$ ......(1)

$\sin 2A=2\sin A\cos A$ ........(2)

$\cos 2A=\cos^2A-\sin^2 A$ .......(3)

$\sin^2A+\cos^2A=1$ .......(4)

Taking the LHS:

$\Rightarrow \cos 3\theta=\cos (\theta +2\theta )$

Using identity 1:

$\Rightarrow \cos (\theta +2\theta )=\cos \theta \cos 2\theta-\sin \theta \sin 2\theta$

Using identities 2 and 3:

$\Rightarrow \cos \theta (\cos ^2\theta-\sin^2 \theta )-\sin \theta (2\sin \theta \cos \theta )\\\\\Rightarrow \cos^3\theta -\sin^2\theta \cos \theta -2\sin^2 \theta \cos \theta \\\\\Rightarrow \cos^3\theta -3\sin^2\theta \cos \theta$

Using identity 4:

$\Rightarrow \cos^3\theta -3(1-\cos^2\theta) \cos \theta\\\\\Rightarrow \cos^3\theta-3\cos \theta+3\cos^3\theta\\\\\Rightarrow 4\cos^3\theta -3\cos \theta$

As, LHS = RHS

Hence proved

5 0

3 years ago

See question above A) 7.2 cm B) 9 cm C) 10.6 cm D) 12 cm

Mila [183]

Answer:

B) 9 cm

Step-by-step explanation:

Just look at the triangle and use Pythagoras theoreum.

a² + b² = c²

a = 9 9 - 4.9 = 5

b = ?

c = 10

5² + b² = 10²

b² = 100 - 25

b² = 75

b = + - SQRT( 75 )

{Only the positive term has a meaning here.}

b = 8.66 rounded that is 9, which is answer B.

3 0

3 years ago