add formula placeholder

package.json

@@ -21,6 +21,7 @@
     "css-loader": "^6.7.3",
     "css-minimizer-webpack-plugin": "^5.0.0",
     "daisyui": "^3.2.1",
+    "mathjs": "^12.4.0",
     "mini-css-extract-plugin": "^2.7.5",
     "postcss": "^8.4.23",
     "postcss-import": "^15.1.0",