Solving Trig Equations: Sin/Tan | Tutorial & Working

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Discussion Overview

The discussion revolves around solving trigonometric equations, specifically focusing on equations involving sine and tangent functions. Participants seek guidance on how to approach these types of problems, particularly those that are more complex than basic examples.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • One participant expresses difficulty in solving equations like sin(x + 30) = 1 and tan(x + 45) = 1, asking for a tutorial or working examples.
  • Another participant suggests substituting u = x + 30 or u = x + 45 to simplify the equations and solve for u, noting the relationship between u and x.
  • Several participants provide a solution for sin(x + 30) = 1, stating that x + 30 = 90 leads to x = 60, with further elaboration on the periodic nature of the sine function, indicating that x = 60 + 360k (in degrees) or x = 60 + 2k pi (in radians), where k is any whole number.

Areas of Agreement / Disagreement

There is a general agreement on the method of solving the equation sin(x + 30) = 1, with multiple participants arriving at the same solution. However, the discussion does not resolve the approach for tan(x + 45) = 1, as it remains unaddressed.

Contextual Notes

Participants do not clarify the assumptions regarding the domain of x or the specific context in which these equations are being solved, which may affect the solutions provided.

Who May Find This Useful

This discussion may be useful for students or individuals seeking to understand methods for solving trigonometric equations, particularly those that involve transformations and periodicity.

Rudders
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Hi,

I'm just stumped on how to solve the following type of trig equation. Could someone show working / a tutorial on how to solve similar equations. I'm fine with simple ones like: 4 + sinx = 3 , but this style has me stumped:

sin(x + 30) = 1
or

tan(x + 45) = 1

Thanks!
 
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Try letting u = x + 30 in the first one, or u= x+45 in the second one. Then, solve it just like you are used to and you attain your values for u. You know the relation between u and x, easy. =]

EDIT: I didn't realize this wasn't the homework forum when I posted. From now on, please only ask homework style questions in the Homework Help forum.
 
sin(x + 30) = 1

( x + 30 ) = 90

x = 90 - 30

x = 60
 
HanQing said:
sin(x + 30) = 1

( x + 30 ) = 90

x = 90 - 30

x = 60

x = 60 + 2k pi

edit: oh wait, in degrees that is:
x = 60 + 360k

Where k is any whole number.

Because sine is repetitive every 360 deg or 2pi rad.
 
ImAnEngineer said:
x = 60 + 2k pi

edit: oh wait, in degrees that is:
x = 60 + 360k

Where k is any whole number.

Because sine is repetitive every 360 deg or 2pi rad.

opps yea you are right ,forgot to include that =.=
 

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