Metamath Proof Explorer


Definition df-tanh

Description: Define the hyperbolic tangent function (tanh). We define it this way for cmpt , which requires the form ( x e. A |-> B ) . (Contributed by David A. Wheeler, 10-May-2015)

Ref Expression
Assertion df-tanh tanh=xcosh-10tanixi

Detailed syntax breakdown

Step Hyp Ref Expression
0 ctanh classtanh
1 vx setvarx
2 ccosh classcosh
3 2 ccnv classcosh-1
4 cc class
5 cc0 class0
6 5 csn class0
7 4 6 cdif class0
8 3 7 cima classcosh-10
9 ctan classtan
10 ci classi
11 cmul class×
12 1 cv setvarx
13 10 12 11 co classix
14 13 9 cfv classtanix
15 cdiv class÷
16 14 10 15 co classtanixi
17 1 8 16 cmpt classxcosh-10tanixi
18 0 17 wceq wfftanh=xcosh-10tanixi