Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Problem
Problem
In any
Δ
A
B
C
\Delta ABC
Δ
A
B
C
,
tan
A
2
−
tan
B
2
tan
A
2
+
tan
B
2
=
\frac{\tan \frac{A}{2} - \tan \frac{B}{2}}{\tan \frac{A}{2} + \tan \frac{B}{2}} =
t
a
n
2
A
+
t
a
n
2
B
t
a
n
2
A
−
t
a
n
2
B
=
a.
a
−
b
a
+
b
\frac{a-b}{a+b}
a
+
b
a
−
b
b.
a
−
b
c
\frac{a-b}{c}
c
a
−
b
c.
a
−
b
a
+
b
+
c
\frac{a-b}{a+b+c}
a
+
b
+
c
a
−
b
d.
c
a
+
b
\frac{c}{a+b}
a
+
b
c
Browse the problem library