Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
Solve the following trigonometric equation for
θ
\theta
θ
in the interval
0
≤
θ
<
2
π
0 \le \theta < 2\pi
0
≤
θ
<
2
π
. a. (i) Show that
cos
2
θ
=
1
2
\cos 2\theta = \dfrac12
cos
2
θ
=
2
1
implies
2
θ
=
2
n
π
±
π
3
,
n
∈
Z
2\theta = 2n\pi \pm \dfrac{\pi}{3},\; n \in \mathbb Z
2
θ
=
2
nπ
±
3
π
,
n
∈
Z
. b. (ii) Hence list all values of
θ
\theta
θ
in the interval
0
≤
θ
<
2
π
0 \le \theta < 2\pi
0
≤
θ
<
2
π
that satisfy the given equation.
Browse the problem library