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4 years ago

9

Write the product as a sum. 9cos(6x) cos(9x)

1 answer:

lys-0071 [83]4 years ago

3 0

Answer:

9/2 [ cos(15x) + cos(3x) ]

Step-by-step explanation:

9cos(6x) . cos(9x) can be expressed as

= 9/2 * 2cos (6x) * cos(9x) next here we will apply the rule

2cosA . cosB = cos(A+B) + cos( A-B)

where A = 6x , B = 9x

hence : 9cos(6x) . cos(9x) expressed as a sum will be

= 9/2 * [cos( 6x+ 9x) + cos( 6x - 9x ) ]

= 9/2 [ cos (15x ) + cos(-3x) ]

the final sum = 9/2 [ cos(15x) + cos(3x) ]

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What are the zero(s) of f(x + 3)?

Pavlova-9 [17]

Answer:

function f(x) = x + 3 has a zero at x = 3 since f(3) = 0.

Step-by-step explanation:

4 0

3 years ago

Answer and work if you have it please?

andrew11 [14]

The answer to your "Question" would be A.

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Hope this helped!

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4 years ago

28/21 = 42/x solve for x

Scilla [17]

28/21=42/x multiply both sides by x

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8 0

3 years ago

Read 2 more answers

Claude spends $315 to rent a car. The car he rents costs $45 per day. He has a coupon for 2 free days. Complete the equation bel

kozerog [31]

He rents for d days, but two days are free, so he pays for only d - 2 days.

The rental fee is $45 per day, so for d - 2 days, he pays 45(d - 2). The total he pays is $315, so the equation is

<u>45</u>(<u>d</u> - <u>2</u>) = <u>315</u>

Now we solve the equation to find d, the number of days.

45(d - 2) = 315

45d - 90 = 315

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The number of days is 9.

6 0

4 years ago

Find the area of a circle with a diameter of 14 meters. Round your answer to the nearest hundredth of a square meter.

Jlenok [28]

<u>To find the area of the circle</u>:

⇒ need to know the formula: $\pi r^{2}$

r: radius or half of diameter's length ⇒ 7 meters

<u>Let's calculate:</u>

$Area = \pi (7)^2=49\pi =153.9380m^3$

<u>The problem asks us to round to the nearest hundreth</u>:

$Area = 153.94m^3$

<u>Answer:</u> $153.94m^3$

Hope that helps!

4 0

2 years ago