Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
Which of the following is identical to
cos
(
x
−
π
4
)
\cos\left(x-\dfrac{\pi}{4}\right)
cos
(
x
−
4
π
)
for every real
x
x
x
? a)
sin
(
x
−
π
4
)
\sin\left(x-\dfrac{\pi}{4}\right)
sin
(
x
−
4
π
)
b)
cos
(
x
+
π
4
)
\cos\left(x+\dfrac{\pi}{4}\right)
cos
(
x
+
4
π
)
c)
sin
(
x
+
π
4
)
\sin\left(x+\dfrac{\pi}{4}\right)
sin
(
x
+
4
π
)
d)
sin
x
+
cos
x
\sin x+\cos x
sin
x
+
cos
x
Browse the problem library