The value of expression
exp1=Re-+8-3PolyLog2,-+16PolyLog2,-2PolyLog2,+4PolyLog2,-+8PolyLog2,+4πArcTan-12
139
2
π
180
2
Log+
1
2
5
2
4
-1+
5
2
2
-1+
5
2
π
3
4
-1+
5
2
π
3
2
-1+
5
2
2ArcTan
1
7
2
-1+
5
2
2ArcTan
1
7
1
7
2
ArcTan
1
7
is
2
2
π
15
It is easy to prove that exp1 is equal to
exp2=-+4πArcTan-12+8-3PolyLog2,-+4Sum(-1)^nCos2nArcTan,{n,1,Infinity}+8SumCos2nArcTan,{n,1,∞}-2SumCos,{n,1,Infinity}+16SumCos,{n,1,∞};
139
2
π
180
1
7
2
ArcTan
1
7
2
Log+
1
2
5
2
4
-1+
5
2
1
n^2
2n
-1+
5
2
1
7
1
n^2
2n
-1+
5
2
1
7
4n
-1+
5
2
nπ
3
2
n
2n
-1+
5
2
nπ
3
2
n
In[]:=
N[exp1,50]==N,50
2
2
π
15
Out[]=
True
In[]:=
N[exp2,50]==N,50
2
2
π
15
Out[]=
True
In[]:=
exp1===
2
2
π
15
Out[]=
False
Myquestionishowcanexp1(orexp2)besimplifiedtoobtain
2
2
π
15