Posted by Kay on Wednesday, October 24, 2007 at 11:00am.
Solve the following interval
0<_ (less than or equal to)0(Theta)<2pi:
1. sin0(theta) + sin2 0(theta) = 0
2. 2cos^20 (theta) + cos0 (theta) 1 = 0

Trig  Reiny, Wednesday, October 24, 2007 at 3:43pm
sinӨ + sin2Ө = 0
recall that sin2Ө = 2sinӨcosӨ
so sinӨ + sin2Ө = 0
sinӨ + 2sinӨcosӨ = 0
sinӨ(1+2cosӨ)=0
sinӨ = 0 or 2cosӨ = 1
sinӨ = 0 or or cosӨ = 1/2
Ө = 0,pi,2pi or Ө=2pi/3,4pi/3
in degrees: 0,180,360,120,240
Answer This Question
Related Questions
 help help helppppmath  1)Use the definitions sin0(theta) = y/r, cos0(theta...
 Math  1)Use the definitions sin0(theta) = y/r, cos0(theta) = x/r and/or tan0(...
 Trigonometry  Thank you STEVE!!!!! Suppose that Cos (theta) = 1/square root 2 ...
 Mathamatics  Solve the following trigonometry identities. a) 1cos2(theta) = ...
 trig  If sin theta is equal to 5/13 and theta is an angle in quadrant II find ...
 Math Trig Please Help!!!  Find exact values for all the solutions to the ...
 math  knowing that 2(theta) can be written as theta + theta, find the ...
 calculus  Find circumference of the circle r=2acos theta. s= Int (0 to 2pi) of ...
 Precalc with Trig  What value(s) of theta (0 less than or equal to theta less ...
 trig  If cosecant of theta equals 3 and cosine of theta is less than zero, find...
More Related Questions