Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
Before integrating,
cos
2
3
x
\cos^2 3x
cos
2
3
x
is most conveniently rewritten as a)
1
2
(
1
+
cos
3
x
)
\tfrac12\bigl(1+\cos 3x\bigr)
2
1
(
1
+
cos
3
x
)
b)
1
2
(
1
+
cos
6
x
)
\tfrac12\bigl(1+\cos 6x\bigr)
2
1
(
1
+
cos
6
x
)
c)
1
4
(
1
+
cos
6
x
)
\tfrac14\bigl(1+\cos 6x\bigr)
4
1
(
1
+
cos
6
x
)
d)
1
2
(
1
−
cos
6
x
)
\tfrac12\bigl(1-\cos 6x\bigr)
2
1
(
1
−
cos
6
x
)
Browse the problem library