How Do You Solve a Quadratic Trigonometric Equation?

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Homework Help Overview

The discussion revolves around solving a quadratic trigonometric equation of the form 6sin²(x) - 6sin(x) + 1 = 0, with the variable x constrained between 0 and 2π. Participants explore various algebraic approaches to find solutions.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Some participants suggest substituting sin(x) with a variable (e.g., u or y) to simplify the equation into a standard quadratic form. Others question the effectiveness of factoring or using the quadratic formula directly on the trigonometric function.

Discussion Status

There is an active exploration of different methods to approach the problem, with participants sharing their thoughts on substitution and the use of the quadratic formula. Some express confusion about the various suggestions and seek clarification on the reasoning behind them.

Contextual Notes

Participants note that the equation is part of a trigonometry chapter, indicating a shared context of learning and understanding quadratic functions within trigonometric scenarios.

ku07
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How do you algebraicly find the solution to this equation

6sin(to power of 2)x-6sinx+1=0

where 0<(or equal to) x <(or equal to) 2pi
 
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Let Sinx = u and then use the binomial theorem.
 
ku07 said:
How do you algebraicly find the solution to this equation

6sin(to power of 2)x-6sinx+1=0

where 0<(or equal to) x <(or equal to) 2pi
If you replace sin(x) by a variable y your equation will be :

[tex]6y^2 -6y + 1 = 0[/tex]

Solve this equation for y. You will get maximum two solutions for y. each solution is equal to sin(x), so you will get two goniometric equations that will be easy to solve.

marlon
 
Im in trig as well and I am confused with some of yalls answers. Couldn't he treat this as a quadratic function. If it were me I would see if I could factor it then set each to 0 and solve; if it doesn't factor I would plug it in the quadratic formula and solve. I am in this same chapter of trig so please let me konw what I am overlooking.
 
seanistic said:
Im in trig as well and I am confused with some of yalls answers. Couldn't he treat this as a quadratic function. If it were me I would see if I could factor it then set each to 0 and solve; if it doesn't factor I would plug it in the quadratic formula and solve. I am in this same chapter of trig so please let me konw what I am overlooking.

yes you can treat it as a quadratic function, that's what marlon did in his post, although you could just leave sin (x) instead of replacing it with y, I believe that just plugging sin(x) = quadratic formula would work just as well, you would then have to do inverse sin on both sides to solve for x
 

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