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Tuesday, January 29, 2013

Solving Trigonometric Equations, 3

Category: Trigonometry

"Published in Newark, California, USA"

Solve for the unknown angle for



Solution:

Consider the given equation



As you notice that the coefficients of Sin 2θ and Cos 2θ are not equal. If you will expand the above equation in order to convert the double angles into single angles, the above equation will be more complicated and it will be hard to simplify and solve the equation. Don't worry, we have a solution or technique to solve this kind of trigonometric equation. 

Draw a right triangle to represent the coefficients of Sin 2θ and Cos 2θ. The coefficient of Sin 2θ will be the adjacent side of a right triangle. The coefficient of Cos 2θ will be the opposite side of a right triangle. Solve for the hypotenuse and get the trigonometric functions as follows


Photo by Math Principles in Everyday Life

From the given equation



Divide both sides of the equation by the hypotenuse which is 2 as follows



Substitute the coefficients of Sin 2θ and Cos 2θ by their equivalent trigonometric functions as follows








 

but 





The above equation becomes









where n = number of revolutions.