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WARRIOR [948]
3 years ago
15

Solve the equation sin x + cos x=cos 2x for 0 27. x

Mathematics
1 answer:
vodka [1.7K]3 years ago
8 0

Answer:

x=\frac{\pi}{4} and x=-\frac{3\pi}{4}

Step-by-step explanation:

We are given that sin x+cos x=cos 2x

We have to solve the given equation for 0\leq x\leq 2\pi

sin x+cos x=cos^2x-sin^2x

Because cos 2x=cos^2-sin^2

sinx+cos x=(sinx +cos x)(sinx-cos x)

1 =sin x-cos x

sin x=cos x

\frac{sinx }{cos x}=1

tan x=1

tan x=\frac{sinx}{cos x}

tan x=tan\frac{\pi}{4}

x=\frac{\pi}{4}

Tan x is positive in I and III quadrant

In III quadrant angle\theta  replace by \theta -\pi

Therefore, tan x=tan (\frac{\pi}{4}-\pi)=tan\frac{\pi-4\pi}{4}=tan\frac{-3\pi}{4}

x=-\frac{3\pi}{4}

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In triangle abc, the length of side and is 10 inches and the length of side be is 17 inches . Which of the following could be th
earnstyle [38]

Answer:

a^2=b^2+c^2.

a^2=10^2+17^2.

a^2=100+289.

a^2=389.

a=√389.

a=19.72~20cm.

5 0
3 years ago
HELP 7th grade math
Charra [1.4K]
1,920? I think .......
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3 years ago
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The domain of u(x) is the set of all real values except 0 and the domain of v(x) is the set of all real values except 2. What ar
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Answer:

A≈1075.21

d Diameter

37

d

r

r

r

d

d

C

A

Using the formulas

A=

π

r

2

d=

2

r

Solving forA

A=

1

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=

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1075.21009

Step-by-step explanation:

5 0
3 years ago
X^4 + x^3 + x^2 + x=0
kifflom [539]
X^4 + x^3 + x^2 + x = 0

x(x^3 + x^2 + x + 1) = 0

x[x^2(x + 1) + 1(x + 1)] = 0

x(x + 1)(x^2 + 1) = 0 ⇔ x = 0 or x + 1 = 0 or x^2 + 1 = 0

x = 0 or x = -1 or x^2 = -1 -false

Answer: x= 0 or x = -1.
4 0
3 years ago
The chi-square test statistic is χ2 = 18.68 and the P-value is between 0.0025 and 0.005. What conclusion should the researcher m
diamong [38]

We don't know what the exact p-value is, but we are told that it's as large as 0.005 which is smaller than alpha = 0.05

Since the p-value is smaller than alpha, this means we <u>reject the null hypothesis</u>.

The way you can remember this is "if the p-value is low, then the null must go". By "low", I mean "smaller than alpha".

Recall that the p-value is the probability of observing that specific test statistic, or larger. So the chances of chi-squared being 18.68 or larger is a probability between 0.0025 and 0.005; there's a very small chance of this happening. The p-value is based entirely on the assumption that the null is correct. But if the null is correct, then the chances of landing on this are very small. We have a contradiction that basically leads to us concluding the null must not be the case. It's not 100% guaranteed of course, but it's fairly strong evidence.

In short, the p-value being smaller than alpha = 0.05 means we reject the null.

In order to accept the null, the p-value must be 0.05 or larger.

5 0
3 years ago
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