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Brums [2.3K]
3 years ago
12

Sin5A/SinA-cos5A/cosA=4cos2A​

Mathematics
1 answer:
irina1246 [14]3 years ago
5 0

Answer:

See Explanation

Step-by-step explanation:

\frac{ \sin5A}{\sin A}  -  \frac{ \cos5A}{\cos A}  = 4\cos2A \\  \\ LHS = \frac{ \sin5A}{\sin A}  -  \frac{ \cos5A}{\cos A}   \\  \\  =  \frac{ \sin5A \:\cos A -  \cos5A \:  \sin A}{\sin A \:\cos A }  \\  \\  =  \frac{ \sin(5A -A )}{\sin A \:\cos A}  \\  \\ =  \frac{ \sin 4A}{\sin A \:\cos A}  \\  \\ =  \frac{ 2\sin 2A \: \cos 2A}{\sin A \:\cos A}  \\  \\ =  \frac{ 2 \times 2\sin A \: \cos A \: \cos 2A}{\sin A \:\cos A}  \\  \\ =  \frac{ 4\sin A \: \cos A \: \cos 2A}{\sin A \:\cos A}  \\  \\ =4\cos 2A \\  \\  = RHS \\  \\ thus \\  \\  \frac{ \sin5A}{\sin A}  -  \frac{ \cos5A}{\cos A}  = 4\cos2A \\  \\ hence \: proved

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Step-by-step explanation:

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99\ in^{2}

Step-by-step explanation:

Area of any triangle could be always calculated as base length multiplied by the height perpendicular to the aforementioned base divided by 2. Therefore:

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Solve each system using substitution:<br> 1. 4x - 5y= -15<br> y= -3x + 22
Bumek [7]
4x - 5y = -15
y = -3x + 22

Plug in your y= equation into the y variable in the other equation

  4x - 5 (y) = -15
            ^^
y = (-3x + 22) = -15

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Combine like terms and add 110 over to -15

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Then, divide the whole equation by 19

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Then, plug in your x into your y= equation

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<em><u>x = 5</u></em>
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3 years ago
Slope of (16, 8) (8, 4)
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Answer:

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2 years ago
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bogdanovich [222]

Answer:

The length of river frontage for each lot are 96.55 ft. 98.85 ft, 101.15 ft and 103.45 ft.

Step-by-step explanation:

See the attached diagram.

The river frontage of 400 ft will be divided into 84 : 86 : 88 : 90 for each lot as AP, BQ, CR, DS and ET all are parallel.

Therefore, PQ : QR : RS : ST = 84 : 86 : 88 : 90 = 42 : 43 : 44 : 45

Let, PQ = 42x, QR = 43x, RS = 44x and ST = 45x

So, (42x + 43x + 44x + 45x) = 400

⇒ 175x = 400

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So, PQ = 42x = 96.55 ft.

QR = 43x = 98.85 ft.

RS = 44x = 101.15 ft and  

ST = 45x = 103.45 ft

(Answer)

6 0
3 years ago
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