diff --git a/std/math/exp.zig b/std/math/exp.zig
index 40eafde39bbd6654836542c31a9ac8a348227556..36c142c87269b5a02b5c71e4eb31778e52529968 100644
--- a/std/math/exp.zig
+++ b/std/math/exp.zig
@@ -31,6 +31,10 @@ fn exp32(x_: f32) -> f32 {
     const sign = i32(hx >> 31);
     hx &= 0x7FFFFFFF;
 
+    if (math.isNan(x)) {
+        return x;
+    }
+
     // |x| >= -87.33655 or nan
     if (hx >= 0x42AEAC50) {
         // nan
@@ -108,6 +112,10 @@ fn exp64(x_: f64) -> f64 {
     const sign = i32(hx >> 31);
     hx &= 0x7FFFFFFF;
 
+    if (math.isNan(x)) {
+        return x;
+    }
+
     // |x| >= 708.39 or nan
     if (hx >= 0x4086232B) {
         // nan
@@ -204,7 +212,6 @@ test "math.exp32.special" {
 }
 
 test "math.exp64.special" {
-    // TODO: Error on release (like pow)
     assert(math.isPositiveInf(exp64(math.inf(f64))));
     assert(math.isNan(exp64(math.nan(f64))));
 }
diff --git a/std/math/expm1.zig b/std/math/expm1.zig
index 327bf27bcd717efe5012f7bac0bdbd476ee67893..7ffc14b9519066637c14e8f10f37a87577f41c90 100644
--- a/std/math/expm1.zig
+++ b/std/math/expm1.zig
@@ -258,7 +258,7 @@ fn expm1_64(x_: f64) -> f64 {
     if (k < 0 or k > 56) {
         var y = x - e + 1.0;
         if (k == 1024) {
-            y = y * 2.0; // TODO: * 0x1.0p1023;
+            y = y * 2.0 * 0x1.0p1022 * 10;
         } else {
             y = y * twopk;
         }
diff --git a/std/math/frexp.zig b/std/math/frexp.zig
index 6de126e723f1b0fd0e52e6e561e4fe1d1c7bffad..3c1849c37d401e3e40f2bfc603aca73623d79660 100644
--- a/std/math/frexp.zig
+++ b/std/math/frexp.zig
@@ -77,8 +77,8 @@ fn frexp64(x: f64) -> frexp64_result {
         }
         return result;
     } else if (e == 0x7FF) {
-        // frexp(nan) = (nan, 0)
         result.significand = x;
+        result.exponent = 0;
         return result;
     }
 
@@ -141,7 +141,6 @@ test "math.frexp32.special" {
 }
 
 test "math.frexp64.special" {
-    // TODO: Error on release mode (like pow)
     var r: frexp64_result = undefined;
 
     r = frexp64(0.0);
diff --git a/std/math/pow.zig b/std/math/pow.zig
index ed851f8b81f54efbca211739b4953c13ff12817b..042e0c3d1ed2df4a69dfdc2aaf32d1741515fcff 100644
--- a/std/math/pow.zig
+++ b/std/math/pow.zig
@@ -179,7 +179,6 @@ fn isOddInteger(x: f64) -> bool {
 test "math.pow" {
     const epsilon = 0.000001;
 
-    // TODO: Error on release
     assert(math.approxEq(f32, pow(f32, 0.0, 3.3), 0.0, epsilon));
     assert(math.approxEq(f32, pow(f32, 0.8923, 3.3), 0.686572, epsilon));
     assert(math.approxEq(f32, pow(f32, 0.2, 3.3), 0.004936, epsilon));
diff --git a/std/math/scalbn.zig b/std/math/scalbn.zig
index 10ca57d99546c2236b1bffe3c695afc40e9bc292..43fac7c00c29a1e0e15f136f0794b4cecde4998f 100644
--- a/std/math/scalbn.zig
+++ b/std/math/scalbn.zig
@@ -48,11 +48,10 @@ fn scalbn64(x: f64, n_: i32) -> f64 {
     var n = n_;
 
     if (n > 1023) {
-        // TODO: Determine how to do the following.
-        // y *= 0x1.0p1023;
+        y *= 0x1.0p1022 * 10.0;
         n -= 1023;
         if (n > 1023) {
-            // y *= 0x1.0p1023;
+            y *= 0x1.0p1022 * 10.0;
             n -= 1023;
             if (n > 1023) {
                 n = 1023;
diff --git a/std/math/sinh.zig b/std/math/sinh.zig
index 019e2f0fbdc593e17866566ff997b2b15e2e8124..e1b001d287508cad049de50c61a301681e6c6b6f 100644
--- a/std/math/sinh.zig
+++ b/std/math/sinh.zig
@@ -28,6 +28,10 @@ fn sinh32(x: f32) -> f32 {
     const ux = u & 0x7FFFFFFF;
     const ax = @bitCast(f32, ux);
 
+    if (x == 0.0 or math.isNan(x)) {
+        return x;
+    }
+
     var h: f32 = 0.5;
     if (u >> 31 != 0) {
         h = -h;
@@ -57,6 +61,10 @@ fn sinh64(x: f64) -> f64 {
     const w = u32(u >> 32);
     const ax = @bitCast(f64, u & (@maxValue(u64) >> 1));
 
+    if (x == 0.0 or math.isNan(x)) {
+        return x;
+    }
+
     var h: f32 = 0.5;
     if (u >> 63 != 0) {
         h = -h;
@@ -112,7 +120,6 @@ test "math.sinh32.special" {
 }
 
 test "math.sinh64.special" {
-    // TODO: Error on release mode (like pow)
     assert(sinh64(0.0) == 0.0);
     assert(sinh64(-0.0) == -0.0);
     assert(math.isPositiveInf(sinh64(math.inf(f64))));
diff --git a/std/math/tanh.zig b/std/math/tanh.zig
index a76de9ce22af7eacfe9c95e83e66fee46d94ee00..c88dc081561be3e31e5e978c6b340f4f6a133fa5 100644
--- a/std/math/tanh.zig
+++ b/std/math/tanh.zig
@@ -30,11 +30,15 @@ fn tanh32(x: f32) -> f32 {
 
     var t: f32 = undefined;
 
+    if (x == 0.0 or math.isNan(x)) {
+        return x;
+    }
+
     // |x| < log(3) / 2 ~= 0.5493 or nan
     if (ux > 0x3F0C9F54) {
         // |x| > 10
         if (ux > 0x41200000) {
-            t = 1.0 + 0 / x;
+            t = 1.0;
         } else {
             t = math.expm1(2 * x);
             t = 1 - 2 / (t + 2);
@@ -71,10 +75,7 @@ fn tanh64(x: f64) -> f64 {
     var t: f64 = undefined;
 
     // TODO: Shouldn't need these checks.
-    if (x == 0.0) {
-        return x;
-    }
-    if (math.isNan(x)) {
+    if (x == 0.0 or math.isNan(x)) {
         return x;
     }
 
@@ -82,7 +83,7 @@ fn tanh64(x: f64) -> f64 {
     if (w > 0x3FE193EA) {
         // |x| > 20 or nan
         if (w > 0x40340000) {
-            t = 1.0; // TODO + 0 / x;
+            t = 1.0;
         } else {
             t = math.expm1(2 * x);
             t = 1 - 2 / (t + 2);
@@ -137,7 +138,6 @@ test "math.tanh64" {
 }
 
 test "math.tanh32.special" {
-    // TODO: Error on release (like pow)
     assert(tanh32(0.0) == 0.0);
     assert(tanh32(-0.0) == -0.0);
     assert(tanh32(math.inf(f32)) == 1.0);