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lisov135 [29]
3 years ago
11

___ cosb =1/2 sin(a+b)+sin(a-b)?

Mathematics
2 answers:
vodomira [7]3 years ago
8 0

Answer:

That would be sina.

Step-by-step explanation:

sin(a+b) = sinacosb + cosasinb

sin(a-b) = sinacosb -  cosasinb

Adding we get  sin(a+b) + sin(a-b) = 2sinaccosb

so sinacosb = 1/2sin(a+b) + sin(a-b)

dem82 [27]3 years ago
6 0

Answer:

sina

Step-by-step explanation:

We have

          sin(a+b) = sina cosb + cosa sinb ---------------------eqn 1

           sin(a-b) = sina cosb - cosa sinb ---------------------eqn 2

eqn 1 + eqn 2

          sin(a+b) + sin(a-b) = sina cosb + cosa sinb + sina cosb - cosa sinb

          sin(a+b) + sin(a-b) = 2sina cosb

          sina\times cosb =\frac{1}{2}(sin(a+b) + sin(a-b))

So answer is sina

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26. Students who take a statistics course are given a pre-test on the concepts and skills for the first chapter of a statistics
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The test statistic value lies to the right of the critical value. So we have sufficient evidence to reject the null hypothesis.

<h3>What are null hypotheses and alternative hypotheses?</h3>

In null hypotheses, there is no relationship between the two phenomenons under the assumption or it is not associated with the group. And in alternative hypotheses, there is a relationship between the two chosen unknowns.

Students who take a statistics course are given a pre-test on the concepts and skills for the first chapter of a statistics course.

Then they are given a post-test once the professor has concluded lecturing on the material.

Pre-test and post-test scores for 4 students in an elementary statistics class are given below.

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Then the null hypotheses and alternative hypotheses will be

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Hₐ: \mu _d > 0

Then the test statistic will be

\rm \overline{x} _d = \dfrac{\Sigma x_d}{n} = \dfrac{15+12+10+1}{4}\\\\\overline{x} _d = 9.5

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The test statistic value is given by

\rm t = \dfrac{\overline{x} _d }{\dfrac{S_d}{\sqrtn}} \\\\t = \dfrac{9.5}{\dfrac{6.02}{\sqrt4}}\\\\t = 3.16

Since this is a right-tailed test, so the critical value is given by

\rm t_{n-1}(\alpha ) = t_3 (0.05) = 2.353

Since the test statistic value lies to the right of the critical value. So we have sufficient evidence to reject the null hypothesis.

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More about the null hypotheses and alternative hypotheses link is given below.

brainly.com/question/9504281

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7 0
2 years ago
Write the standard equation of the circle with the given center and passes through the given point. Center (7,-2); Point= (1,-6)
vodomira [7]

Answer:

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Step-by-step explanation:

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r = √ [6² + 4²] ) = √(36 + 16) = √52 = √4√13 = 2√13.

Then the desired equation is (x - 7)² + (y + 2)² = (2√13)²

6 0
3 years ago
The 2nd term of an exponential sequence is 9 while the 4th term is 81.find the common ratio,the first term and the sum of the fi
Thepotemich [5.8K]

Answer:

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VMariaS [17]

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