$MathMaster logo$

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

116 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 value of tangent of an angle when sine is 3/5?

+

Math question: What is the limit as x approaches 0 of (sin(x)/x)?

+

Math Question: Solve the quadratic equation 2x^2 - 5x + 3 = 0.

+

New questions in Mathematics

How to find the value of x and y which satisfy both equations x-2y=24 and 8x-y=117

Let 𝑢 = 𝑓(𝑥, 𝑦) = (𝑒^𝑥)𝑠𝑒𝑛(3𝑦). Check if 9((𝜕^2) u / 𝜕(𝑥^2)) +((𝜕^2) 𝑢 / 𝜕(𝑦^2)) = 0

The ratio of tomatoes to red apples is 2:5. If there are 20 tomaoes in the garden, how many red apples are there?

Credit title that represents a payment order. This model, which emerged in Brazil, can only be issued in two specific situations: in the purchase and sale of commercial products or in the provision of services. Select the correct alternative: Question 6Answer The. Present value B. Promissory note w. Present value d. Duplicate It is. Bill of exchange

2x2 and how much?

Pedro had 80% of the amount needed to buy a game. Of this amount, you spent 15% on a watch and therefore, you will need to add another R$640.00 to purchase this game. Is the value of the game?

find all matrices that commute with the matrix A=[0 1]

During a fishing trip Alex notices that the height h of the tide (in metres) is given by h=1−(1/2)*cos(πt/6) where t is measued in hours from the start of the trip. (a) Enter the exact value of h at the start of the trip in the box below.

28 is 92 percent of what?

Your boss asks you to plan the sample size for a randomized, double-blind, controlled trial in the clinical development of a cure for irritable bowl disease. Current standard treatment shall be compared with a new treatment in this trial. The S3-guideline of AWM demonstrated a mean change of the summary score of the validated health related quality of life questionnaire at 8 weeks of 16 with standard deviation 23 under standard treatment. You quote the drop-out rate of 11% from literature (previous phase of clinical development). Your research yielded a clinically important effect of 4 that has been found to be the Minimal Clinically Important Difference (MCID). In order to demonstrate superiority of the new treatment over standard of care, you assume that the change in of the summary score of the validated health related quality of life questionnaire follows a normal distribution, and that the standard deviation is the same for both treatments. How many patientes would one need to recruit for the trial to demonstrate the clinically interesting difference between treatments at significance level 5% with 95% power?

Given (3x+2)E [2;14] how much money (in soles) does Sophia have if numerically it is the greatest value of x?

A researcher is interested in voting preferences on change of the governing constitution in a certain country controlled by two main parties A and B. A questionnaire was developed and sent to a random sample of voters. The cross tabs are as follows Favour Neutral Oppose Membership: Party A 70 90 85 Party B 50 50 155 Test at α = 0.05 whether party membership and voting preference are associated and state the conditions required for chi-square test results to be valid.

30y - y . y = 144

User One of the applications of the derivative of a function is its use in Physics, where a function that at every instant t associates the number s(t), this function s is called the clockwise function of the movement. By deriving the time function we obtain the velocity function at time t, denoted by v(t). A body has a time function that determines its position in meters at time t as S(t)=t.³√t+2.t . Present the speed of this body at time t = 8 s.

ind the z-score for which 72% of the distribution's area lies between -z and z. -1.7417, 1.7417 -1.1538, 1.1538 -1.0803, 1.0803 -2.826, 2.826

Evaluate ab+dc if a=56 , b=−34 , c=0.4 , and d=12 . Write in simplest form.

A 20-year old hopes to retire by age 65. To help with future expenses, they invest $6 500 today at an interest rate of 6.4% compounded annually. At age 65, what is the difference between the exact accumulated value and the approximate accumulated value (using the Rule of 72)?

What is the percentage of nitrogen abundance in copper dinatrate Cu(NO3)2

A gas is leaking at 3.5ft3/min in a room of 2.9m by 6.9ft by 15.7m. How long would it take (in seconds) for 22% of the room to reach the LFL, if the gas has a LFL of 2.51%?