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Solving a linear equation involving the sine function

Find all possible exact solutions for the equation sin t = 1 2 .

Solving for all possible values of t means that solutions include angles beyond the period of 2 π . From [link] , we can see that the solutions are π 6 and 5 π 6 . But the problem is asking for all possible values that solve the equation. Therefore, the answer is

π 6 ± 2 π k   and   5 π 6 ± 2 π k

where k is an integer.

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Given a trigonometric equation, solve using algebra .

  1. Look for a pattern that suggests an algebraic property, such as the difference of squares or a factoring opportunity.
  2. Substitute the trigonometric expression with a single variable, such as x or u .
  3. Solve the equation the same way an algebraic equation would be solved.
  4. Substitute the trigonometric expression back in for the variable in the resulting expressions.
  5. Solve for the angle.

Solve the trigonometric equation in linear form

Solve the equation exactly: 2 cos θ 3 = 5 , 0 θ < 2 π .

Use algebraic techniques to solve the equation.

2 cos θ 3 = 5         2 cos θ = 2           cos θ = 1                θ = π
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Solve exactly the following linear equation on the interval [ 0 , 2 π ) : 2 sin x + 1 = 0.

x = 7 π 6 , 11 π 6

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Solving equations involving a single trigonometric function

When we are given equations that involve only one of the six trigonometric functions, their solutions involve using algebraic techniques and the unit circle (see [link] ). We need to make several considerations when the equation involves trigonometric functions other than sine and cosine. Problems involving the reciprocals of the primary trigonometric functions need to be viewed from an algebraic perspective. In other words, we will write the reciprocal function, and solve for the angles using the function. Also, an equation involving the tangent function is slightly different from one containing a sine or cosine function. First, as we know, the period of tangent is π , not 2 π . Further, the domain of tangent is all real numbers with the exception of odd integer multiples of π 2 , unless, of course, a problem places its own restrictions on the domain.

Solving a problem involving a single trigonometric function

Solve the problem exactly: 2 sin 2 θ 1 = 0 , 0 θ < 2 π .

As this problem is not easily factored, we will solve using the square root property. First, we use algebra to isolate sin θ . Then we will find the angles.

2 sin 2 θ 1 = 0        2 sin 2 θ = 1          sin 2 θ = 1 2        sin 2 θ = ± 1 2            sin θ = ± 1 2 = ± 2 2                 θ = π 4 , 3 π 4 , 5 π 4 , 7 π 4
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Solving a trigonometric equation involving cosecant

Solve the following equation exactly: csc θ = 2 , 0 θ < 4 π .

We want all values of θ for which csc θ = 2 over the interval 0 θ < 4 π .

csc θ = 2 1 sin θ = 2 sin θ = 1 2       θ = 7 π 6 , 11 π 6 , 19 π 6 , 23 π 6
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Solving an equation involving tangent

Solve the equation exactly: tan ( θ π 2 ) = 1 , 0 θ < 2 π .

Recall that the tangent function has a period of π . On the interval [ 0 , π ) , and at the angle of π 4 , the tangent has a value of 1. However, the angle we want is ( θ π 2 ) . Thus, if tan ( π 4 ) = 1 , then

θ π 2 = π 4 θ = 3 π 4 ± k π

Over the interval [ 0 , 2 π ) , we have two solutions:

3 π 4   and  3 π 4 + π = 7 π 4
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Questions & Answers

differentiate between demand and supply giving examples
Lambiv Reply
differentiated between demand and supply using examples
Lambiv
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Lambiv
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appreciation
Eliyee
explain perfect market
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In economics, a perfect market refers to a theoretical construct where all participants have perfect information, goods are homogenous, there are no barriers to entry or exit, and prices are determined solely by supply and demand. It's an idealized model used for analysis,
Ezea
What is ceteris paribus?
Shukri Reply
other things being equal
AI-Robot
When MP₁ becomes negative, TP start to decline. Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of lab
Kelo
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of labour (APL) and marginal product of labour (MPL)
Kelo
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Shukri
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Shukri
what is monopoly mean?
Habtamu Reply
What is different between quantity demand and demand?
Shukri Reply
Quantity demanded refers to the specific amount of a good or service that consumers are willing and able to purchase at a give price and within a specific time period. Demand, on the other hand, is a broader concept that encompasses the entire relationship between price and quantity demanded
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Economic growth as an increase in the production and consumption of goods and services within an economy.but Economic development as a broader concept that encompasses not only economic growth but also social & human well being.
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Jabir
What do you think is more important to focus on when considering inequality ?
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it is a curve that we get after connecting the pareto optimal combinations of two consumers after their mutually beneficial trade offs
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In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities, where neither p
Cornelius
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities,
Cornelius
Suppose a consumer consuming two commodities X and Y has The following utility function u=X0.4 Y0.6. If the price of the X and Y are 2 and 3 respectively and income Constraint is birr 50. A,Calculate quantities of x and y which maximize utility. B,Calculate value of Lagrange multiplier. C,Calculate quantities of X and Y consumed with a given price. D,alculate optimum level of output .
Feyisa Reply
Answer
Feyisa
c
Jabir
the market for lemon has 10 potential consumers, each having an individual demand curve p=101-10Qi, where p is price in dollar's per cup and Qi is the number of cups demanded per week by the i th consumer.Find the market demand curve using algebra. Draw an individual demand curve and the market dema
Gsbwnw Reply
suppose the production function is given by ( L, K)=L¼K¾.assuming capital is fixed find APL and MPL. consider the following short run production function:Q=6L²-0.4L³ a) find the value of L that maximizes output b)find the value of L that maximizes marginal product
Abdureman
types of unemployment
Yomi Reply
What is the difference between perfect competition and monopolistic competition?
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Source:  OpenStax, Precalculus. OpenStax CNX. Jan 19, 2016 Download for free at https://legacy.cnx.org/content/col11667/1.6
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