Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Problem
Problem
In a
Δ
A
B
C
\Delta ABC
Δ
A
B
C
,
c
cos
2
A
2
+
a
cos
2
C
2
=
3
b
2
c \cos^2 \frac{A}{2} + a \cos^2 \frac{C}{2} = \frac{3b}{2}
c
cos
2
2
A
+
a
cos
2
2
C
=
2
3
b
, then show
a
,
b
,
c
a, b, c
a
,
b
,
c
are in AP.
Browse the problem library