[DOC] update docs of activation op (#46556)

paddle/fluid/operators/activation_op.cc

@@ -246,7 +246,8 @@ $$out = \\frac{1}{\\sqrt{x}}$$
 UNUSED constexpr char CeilDoc[] = R"DOC(
 Ceil Operator. Computes ceil of x element-wise.
 
-$$out = \\lceil x \\rceil$$
+..  math::
+    out = \left \lceil x \right \rceil
 
 )DOC";
 
@@ -262,7 +263,8 @@ Cosine Operator. Computes cosine of x element-wise.
 
 Input range is `(-inf, inf)` and output range is `[-1,1]`.
 
-$$out = cos(x)$$
+..  math::
+    out = cos(x)
 
 )DOC";
 
@@ -292,7 +294,10 @@ $$out = sinh(x)$$
 UNUSED constexpr char CoshDoc[] = R"DOC(
 Cosh Activation Operator.
 
-$$out = cosh(x)$$
+Input range `(-inf, inf)`, output range `(1, inf)`.
+
+..  math::
+    out = \frac{exp(x)+exp(-x)}{2}
 
 )DOC";
 
@@ -393,11 +398,12 @@ class AcosOpMaker : public framework::OpProtoAndCheckerMaker {
  public:
   void Make() override {
     AddInput("X", "Input of acos operator");
-    AddOutput("Out", "Output of acos operator");
+    AddOutput("Out", "Tensor, same shape and dtype as input");
     AddComment(R"DOC(
 Arccosine Operator.
 
-$$out = \cos^{-1}(x)$$
+..  math::
+    out = \cos^{-1}(x)
 
 )DOC");
   }
@@ -409,11 +415,12 @@ class AsinOpMaker : public framework::OpProtoAndCheckerMaker {
     AddInput("X",
              "Input of asin operator, an N-D Tensor, with data type float32, "
              "float64 or float16.");
-    AddOutput("Out", "Output of asin operator");
+    AddOutput("Out", "Tensor, same shape and dtype as input.");
     AddComment(R"DOC(
 Arcsine Operator.
 
-$$out = \sin^{-1}(x)$$
+..  math::
+    out = \sin^{-1}(x)
 
 )DOC");
   }
@@ -425,11 +432,12 @@ class AtanOpMaker : public framework::OpProtoAndCheckerMaker {
     AddInput("X",
              "Input of atan operator, an N-D Tensor, with data type float32, "
              "float64 or float16.");
-    AddOutput("Out", "Output of atan operator");
+    AddOutput("Out", "Tensor, same shape and dtype as input x");
     AddComment(R"DOC(
 Arctangent Operator.
 
-$$out = \tan^{-1}(x)$$
+..  math::
+    out = \tan^{-1}(x)
 
 )DOC");
   }