$MathMaster logo$

MathMaster

Home
general
given cos26 k find cos13

Question

given cos26=k find cos13

93

likes

465 views

Answer to a math question given cos26=k find cos13

$Expert avatar$

4.9

114 Answers

cos(2θ) = 2 \times cos^2(θ) - 1

cos^2(θ) = \frac{(cos(2θ) +1)}{2}

cos^2(13) = \frac {cos(26) +1}{2}

cos^2(13) = \frac{k +1}{2}

\cos\:13\:=\pm\sqrt{\left(\frac{k+1}{2}\right)}}

Frequently asked questions (FAQs)

What is the median of the following dataset: 6, 9, 12, 15, 18?

+

Math question: Differentiate f(x) = sin(2x) + cos(3x) with respect to x.

+

What is the value of x in radians if x is given in degrees as 90?

+

New questions in Mathematics

calculate the derivative by the limit definition: f(x) = 6x^3 + 2

The patient is prescribed a course of 30 tablets. The tablets are prescribed “1 tablet twice a day”. How many days does a course of medication last?

Kayla has $8,836.00 in her savings account. The bank gives Kayla 5%of the amount of money in account as a customer bonus. What amount of money does the bank give Kayla? Justify your answer on a 6th grade level.

Suppose that a device has been created that launches objects at ground level and that its operation is modeled by the function h(x) = -4×² + 256x, with h being the height (in meters) and x being the distance (in meters) What is the maximum height that the object reaches?

For a temperature range between -3 degrees Celsius to 5 degrees Celsius, what is the temperature range in degrees Farenheight

Suppose 50% of the doctors and hospital are surgeons if a sample of 576 doctors is selected what is the probability that the sample proportion of surgeons will be greater than 55% round your answer to four decimal places

The sum of two numbers is equal to 58 and the largest exceeds by at least 12. Find the two numbers

How many anagrams of the word SROMEC there that do not contain STROM, MOST, MOC or CEST as a subword? By subword is meant anything that is created by omitting some letters - for example, the word EMROSCT contains both MOC and MOST as subwords.

It is known that the content of milk that is actually in a bag distributes normally with an average of 900 grams and variance 25 square grams. Suppose that the cost in pesos of a bag of milk is given by 𝐶(𝑥) = { 3800 𝑠𝑖 𝑥 ≤ 890 4500 𝑠𝑖 𝑥 > 890 Find the expected cost.

The ninth term of a given geometric progression, with reason q , is 1792, and its fourth term is 56. Thus, calculate the fourth term of another geometric progression, whose ratio is q +1 and whose first term is equal to the first term of the first P.G. described.

From 1975 through 2020 the mean annual gain of the Dow Jones Industrial Average was 652. A random sample of 34 years is selected from this population. What is the probability that the mean gain for the sample was between 400 and 800? Assume the standard deviation is 1539

What is 75 percent less than 60

Find the equation of a straight line that has slope 3 and passes through the point of (1, 7) . Write the equation of the line in general forms

Select a variable and collect at least 50 data values. For example, you may ask the students in the college how many hours they study per week or how old they are, etc. a. Explain what your target population was. b. State how the sample was selected. c. Summarise the data by using a frequency table. d. Calculate all the descriptive measures for the data and describe the data set using the measures. e. Present the data in an appropriate way. f. Write a paragraph summarizing the data.

Find the orthogonal projection of a point A = (1, 2, -1) onto a line passing through the points Pi = (0, 1, 1) and P2 = (1, 2, 3).

An export company grants a bonus of $100,000 pesos to distribute among three of its best employees, so that the first receives double the second and the latter receives triple the third. How much did each person receive?

Write an equation of the affine function whose graph is perpendicular to the graph of f(x) = 5x − 1 and passes through the point (5, 20).