How do you solve: #sin2x - sinx = 0#? Trigonometry Trigonometric Identities and Equations Proving Identities 2 Answers Kalyanam S. May 28, 2018 #color(maroon)(x = 0 , color(crimson)(x = pi/3# or #color(crimson )(60^@# Explanation: #sin 2x - sin x = 0# #=> 2 sin x cos x - sin x = 0# #=> sin x * (2 cos x - 1) = 0# #=> sin x = 0, cos x = 1/2# #color(maroon)(x = 0 , color(crimson)(x = pi/3# or #color(crimson )(60^@# Answer link Dean R. May 28, 2018 # x = 180^circ k or x= \pm 60^circ + 360^circ k quad # integer #k# Explanation: #sin 2x - sin x = 0# #2 sin x cos x - sin x = 0# #sin x (2 cos x -1) = 0# #sin x = 0 or cos x = 1/2 # # x = 180^circ k or x= \pm 60^circ + 360^circ k quad # integer #k# Answer link Related questions What does it mean to prove a trigonometric identity? How do you prove #\csc \theta \times \tan \theta = \sec \theta#? How do you prove #(1-\cos^2 x)(1+\cot^2 x) = 1#? How do you show that #2 \sin x \cos x = \sin 2x#? is true for #(5pi)/6#? How do you prove that #sec xcot x = csc x#? How do you prove that #cos 2x(1 + tan 2x) = 1#? How do you prove that #(2sinx)/[secx(cos4x-sin4x)]=tan2x#? How do you verify the identity: #-cotx =(sin3x+sinx)/(cos3x-cosx)#? How do you prove that #(tanx+cosx)/(1+sinx)=secx#? How do you prove the identity #(sinx - cosx)/(sinx + cosx) = (2sin^2x-1)/(1+2sinxcosx)#? See all questions in Proving Identities Impact of this question 24597 views around the world You can reuse this answer Creative Commons License