Algebra 2/trig june 2010 regents? Question number 37

what are all values for theta in sin2 theta=sin theta?
0 les than equal to theta les than equal to 360 degrees.

http://www.youtube.com/watch?v=ElRvBhzMY…
This guy will tell you the answer

1) As given sin(2θ) = sin(θ)

2) Applying sin(2θ) = 2sin(θ)cos(θ), the given equation is

2sin(θ)cos(θ) = sin(θ)

3) Rearranging, 2sin(θ)cos(θ) - sin(θ) = 0

4) Factorizing, sin(θ){2cos(θ) - 1} = 0

==> Either sin(θ) = 0 or 2cos(θ) - 1 = 0, cos(θ) = 1/2

==> If sin(θ) = 0, then θ = 0 or π or 2π

If cos(θ) = 1/2, then (θ) = π/3 or 5π/3

Thus θ = {0, π/3, π, 5π/3, 2π}

try this site...all the questions are worked out for that regents....http://www.jmap.org/JMAP/JMAPArchives/EXAMANSWERS/ALGEBRA2/0610a2ans.pdf


did you understand how to get number 29???

This video here is the exact answer to your question:

http://www.youtube.com/watch?v=VpIlo-HdDU8

Hope it helps! :)