SOLUTION: Solve the equation on the interval 0 less than or equal to theta which is less than 2pi. cos(2theta) + 6sin2theta = 4 Thank you!!

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Question 521115: Solve the equation on the interval 0 less than or equal to theta which is less than 2pi.
cos(2theta) + 6sin2theta = 4
Thank you!!
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


I assume you mean:



(Note, use the caret mark (Shift-6: ^) to indicate raising to a power as in sin^2(theta))

Use the Double Angle formula for cosine:



Use the Pythagorean Identity to change the cosine term to a sine term:



A little Algebra Music, Maestro:





You will find these two values four places on the unit circle in the interval



John

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