We have to solve (1 + cos 2x) / 2 = sin (-2x)
(1 + cos 2x) / 2 = sin (-2x)
=> -(1 + cos 2x) / 2 = sin (2x)
=> -( 1 + (cos x)^2 - (sin x)^2)/ 2 = 2 sin x cos x
=> -1 - (cos x)^2 + (sin x)^2 = 4 sin x cos x
=> -(cos x)^2 - (sin x)^2 - (cos x)^2 + (sin x)^2 =4 sin x cos x
=> - 2(cos x)^2 = 4 sin x cos x
=> -2 cos x = 4 sin x
=> sin x / cos x = -2/4
=> tan x = -1/2
x = arc tan (-1/2)
Therefore x = arc tan ( -1/2) + n*pi
We’ll help your grades soar
Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.
- 30,000+ book summaries
- 20% study tools discount
- Ad-free content
- PDF downloads
- 300,000+ answers
- 5-star customer support
Already a member? Log in here.
Are you a teacher? Sign up now