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natali 33 [55]
2 years ago
5

Cos3A ×cos2A =cos A ×cos 2A -sin4A×sin A=prove it

Mathematics
1 answer:
bogdanovich [222]2 years ago
8 0

Answer:

Step-by-step explanation:

cosA×cos 2A-sin4A×sinA

=cosAcos2A-2sin2Acos2A sin A

=cos 2A(cosA-2sin2AsinA)

=cos 2A(cosA-2×2sinAcosAsin A)

=cos2A×cosA(1-4sin²A)

=cos 2AcosA(1-4(1-cos²A))

=cos2A×cosA(1-4+4cos²A)

=cos 2A(-3cosA+4cos³A)

=cos 2A(4cos³A-3cosA)

=cos 2A×cos3A

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A recipe for lemon bars called for 9" X 13" pan. How many 1" X 1" bars can be cut? How many 2" X 2" bars can be cut? How much is
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The number of bars which can be cut for the 1" X 1" and 2" X 2" square bars are; 117 and 29 units respectively.

<h3>How many bars can be cut from the pan in each case?</h3>

The total area of the given pan can be evaluated as follows;

Area = length × width

= 9 × 13

= 117 square units.

Hence, the number of 1" X 1" bars can be cut which can be cut from the pan;

= 117/(1×1)

= 117 1" X 1" bars.

For the 2" X 2" square bars, we have;

= 117/(2×2);

29 remainder 1 square unit.

Ultimately, one square unit of the pan is wasted for the 2" X 2" square bars.

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2 years ago
You give 1/2 up a $46,000 salary to go back to school for 5 years. The total cost for going to school is $22,000. How much money
Ket [755]

The individual needs to earn $74,750 salary per year in order to recover the investment in 4 years.

What salary amount makes the individual as they were without a salary cut?

By the time the individual resumes back for work after 5 years, they need to earn their previous salary of $46,000 and recover the lost salaries, which is half of $46,000 lost in the last 5 years.

Total salaries lost=1/2*$46,000*5years

Total salaries lost=$115,000

Because the salaries lost needs to be recovered over 4 years, the extra earnings over and above the $46,000 in 4 years is the total salaries lost divided by 4 years

extra salary per year=$115,000/4

extra salary per year=$28,750

Total salary now=prior salary+ extra salary per year

Total salary now=$46,000+$28,750

Total salary now=$74,750

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4 0
2 years ago
What is the solution to the following equation?
lara31 [8.8K]
C is the correcr answer
7 0
3 years ago
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How many pints are in 6.5 gallons?
stich3 [128]

Answer:

52 pints in 6.5 gallons.

Step-by-step explanation:

6.5 *8= 52

3 0
3 years ago
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the value of a famous painting is increasing at a rate of 6% per year and has a value of 800000 in the year of 2000. what is the
rjkz [21]
I'm not 100% sure but I think this is how you solve it:
1. 800,000 x 0.06 = 48,000
2. 48,000 x 17 = 816,000
3. 800,000 + 816,000 = 1,616,000
The painting is worth $1,616,000 in 2017.
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3 years ago
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