Answer:
w = π/2
Step-by-step explanation:
I used trig identities (double angle) to solve this problem.
Step 1: Rearrange problem
2cos²(w) - cos(w) - 1 = 0
2cos²(w) - 1 - cos(w) = 0
Step 2: Trig Identity
cos2w - cos(w) = 0
Step 3: Combine like terms
cosw = 0
Step 4: Solve
w = cos^-1(0)
w = π/2
I may have done it wrong so don't rely too much on me
Answer:
Step-by-step explanation:
2 cos²(w)-cos w-1=0
2 cos² w-2cos w+cos w-1=0
2 cos w(cos w-1)+(cos w-1)=0
(cos w-1)(2 cos w+1)=0
either cos w=1=cos 0=cos (0+2nπ)
w=2nπ,n∈I
or 2 cos w+1=0
cos w=-1/2=-cos (π/3)=cos ((2n+1)π±π/3)
w=[(2n+1)±1/3]π,
n∈ I
