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11Alexandr11 [23.1K]
4 years ago
15

Solve 2cos^2x+5cosx+2=0

Mathematics
1 answer:
Nuetrik [128]4 years ago
6 0
2cos^2x+5cosx+2=0\\
x\in\\
\Delta=b^2-4ac\\
\Delta=9\\
\sqrt{\Delta}=3\\
cosx=1\\
or\\
cosx=-6\\
-6\notin\\

Then using trygonometric table or a graph we read that:
cosx=1\Leftrightarrow(x)=0

Period of cosinus function = 2π
So the last answer is x=0+2k\pi\\
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Errol bought a skateboard helmet on sale at 40% off. The original price was $49.95. What is the amount of discount?
Rudiy27

Answer:

Discount = \$19.98

Step-by-step explanation:

Given

Amount = \$49.95

Price\ Off = 40\%

Required

Determine the discount

The discount is calculated by multiplying the price off by the original price:

Discount = Amount * Price\ Off

Discount = \$49.95 * 40\%

Convert % to decimal

Discount = \$49.95 * 0.40

Discount = \$19.98

<em>Hence, the amount of discount is $19.98</em>

6 0
3 years ago
A country's population in 1995 was 65 million. In 1998 it was 69 million. Estimate the population in 2006 using the exponential
LenKa [72]
80 million. 2001= 73 million. 2004=77 billion. 2007=81 million. Take away a year, maybe take away one million.
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3 years ago
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What is the value of -3|15 -s|+2s^3 when s=-3
gayaneshka [121]
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3 0
3 years ago
What is 3.242424 as a mixed number
kicyunya [14]

Answer:

Step-by-step explanation:

The answer is 3 /8/33.

step by step explanation

First, we can write:

x

=

3

.

¯¯¯¯

24

Next, we can multiply each side by

100

giving:

100

x

=

324

.

¯¯¯¯

24

Then we can subtract each side of the first equation from each side of the second equation giving:

100

x

−

x

=

324

.

¯¯¯¯

24

−

3

.

¯¯¯¯

24

We can now solve for

x

as follows:

100

x

−

1

x

=

(

324

+

0

.

¯¯¯¯

24

)

−

(

3

+

0

.

¯¯¯¯

24

)

(

100

−

1

)

x

=

324

+

0

.

¯¯¯¯

24

−

3

−

0

.

¯¯¯¯

24

99

x

=

(

324

−

3

)

+

(

0

.

¯¯¯¯

24

−

0

.

¯¯¯¯

24

)

99

x

=

321

+

0

99

x

=

321

99

x

99

=

321

99

99

x

99

=

3

×

107

3

×

33

x

=

3

×

107

3

×

33

x

=

107

33

Now, we can convert this improper fraction to a mixed number:

x

=

107

33

=

99

+

8

33

=

99

33

+

8

33

=

3

+

8

33

=

3

8

33

3

.

¯¯¯¯

24

=

3

8

33

6 0
3 years ago
Read 2 more answers
If 1kg is the weight of seven apples, how many apples are in 2K grams?
Elena L [17]

Hey here is your answer

==========================

1kg = 1000g

given,

1kg = 7 apples

1000g = 7 apples

then,

2000g = 2 × 1000g

= 2 × 7 apples

= 14 apples

===========================

hope it may helpful to you

plzz mark me as brain list

Read more on Brainly.in - https://brainly.in/question/3574692#readmore

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3 years ago
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