SOLUTION: How do you solve: where Θ, 0� ≤ Θ

SOLUTION: How do you solve: where Θ, 0� ≤ Θ < 360� cos2Θ = cosΘ

Question 445380: How do you solve: where Θ, 0� ≤ Θ < 360�
cos2Θ = cosΘ
Answer by htmentor(1343) (Show Source): You can put this solution on YOUR website!

Using the identity we have

This is a quadratic in . Let x = . Then we can write:

Solve for x using the quadratic formula:

This gives x = 1, -1/2
Since we need to find values for which give ,
The inv. cos of 1 = 0 deg.
The inv. cos of -1/2 = 120 deg.
Since the ranges from 0 to 360 deg. and since = 240 deg., we need to include 240 deg.
So the answers are deg, deg, deg
RELATED QUESTIONS
How do you solve cos2Θ = cosΘ where Θ, 0� ≤ Θ < 360� (answered by poliphob3.14)

if 0≤Θ<360�, solve sec^2 (2Θ) +2sec(2Θ) =... (answered by KMST)

Factor sin8Θ + 2sin4Θcos4Θ + cos8Θ? Verify (cos2Θ +... (answered by Alan3354)

Solve on indicated interval: 0�≤Θ<2π Find EXACT answers.... (answered by richard1234)

Solve secΘ = -2 for all Θ such that 0� ≤ Θ ≤ 360�. Round you... (answered by solver91311)

Solve secΘ = -2 for all Θ such that 0� ≤ Θ ≤ 360�. Round you... (answered by Boreal)

I'm Stumped. Solve each equation on the indicated interval. Find EXACT answer... (answered by lwsshak3)

secΘ-2tanΘ=0 (answered by tommyt3rd,solver91311)

Hi, I'm very lost. The direction said to find the exact value of Θ in the interval (answered by stanbon)

SOLUTION: How do you solve: where &#920;, 0� &#8804; &#920; < 360� cos2&#920; = cos&#920;

SOLUTION: How do you solve: where Θ, 0� ≤ Θ < 360� cos2Θ = cosΘ