$MathMaster logo$

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)

Q: What is the value of f(x) = 1/x when x = 2?

+

What is the unit vector representing the direction of vector v = (3, -4) in the xy-plane?

+

What is the variance of the dataset: [2, 4, 6, 8, 10]?

+

New questions in Mathematics

A particular employee arrives at work sometime between 8:00 a.m. and 8:50 a.m. Based on past experience the company has determined that the employee is equally likely to arrive at any time between 8:00 a.m. and 8:50 a.m. Find the probability that the employee will arrive between 8:05 a.m. and 8:40 a.m. Round your answer to four decimal places, if necessary.

A software company incurs a cost of $50 per license sold plus $5,000 in fixed costs. How many licenses should you sell to minimize total costs?

calculate the following vector based on its base vectors a= -18i,26j

A consulting company charges a fee of $50 per hour for consulting. If their monthly fixed costs are $1,000 and they want to make a monthly profit of $2,500, how many consulting hours should they bill per month?

[(36,000,000)(0.000003)^2]divided(0.00000006)

(6.2x10^3)(3x10^-6)

The equation of the circle that passes through (5,3) and is tangent to the abscissa axis at x=2 is a.(x-2)^2 (y 3)^2 = 9 b.(x-2)^2 (y-3)^2 = 9 c.(x-2)^2 (y-3)^2 = 4 d.(x-2)^2 (y 1)^2 = 4 e.(x-2)^2 (y-1)^2 = 4

How many different ways can a psychology student select 5 subjects from a pool of 20 subjects and assign each one to a different experiment?

Subscribers to the FAME magazine revealed the following preferences for three categories: Fashion 30, Athletics 24 and Business 15. Following these frequencies of observation, compute the chi-square test statistic. At the 0.05 level of significance, would you conclude they are similar?

How to do 15 x 3304

Quadratic equation 2X = 15/X + 7

We have received our p&l statement back from accounts. The board has asked for an innovation hub. What items should we prioritise reviewing to decide if we can afford an innovation hub?

List the remaining zeros of the polynomial with the given zeros Zeros are: 2, 3i, and 3 + i

15.A newly married couple purchased a home with a $123710 down payment. They financed the remaining balance of the home with a mortgage. Their payments were $15395 at the end of every six months for 23 years and the interest rate was 10.6%, compounded semi-annually. How much did they purchase their home for. Enter to the nearest cent (two decimals). Do not use $ signs or commas in the answer.

A diamond ring was reduced from $999.99 to $689.99. Find the percent reduction in the price. Round the answer to the nearest tenth of a percent, if necessary.

Cuboid containers (open at the top) should be examined with regard to their volume. The figure below shows a network of such containers (x ∈ Df). Determine a function ƒ (assignment rule and definition area D) that describes the volume of these containers and calculate the volume of such a container if the content of the base area is 16 dm². Show that this function f has neither a local maximum nor a global maximum

2 - 6x = -16x + 28

Define excel and why we use it?