# Backpropagation - math notation

{% embed url="<https://youtu.be/2mSysRx-1c0>" %}

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LWzztwo176gse1ZaWWZ%2F-LX-0x9pxzdjhDyPF_01%2FScreen%20Shot%202019-01-24%20at%201.23.22%20PM.png?alt=media\&token=968ab3e8-09af-4371-8ff8-0bcc30caf6e3)

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-3TPYpuFpCFisMImv%2FScreen%20Shot%202019-01-24%20at%201.34.03%20PM.png?alt=media\&token=bcc7bfda-d3f7-497c-9aaf-df884cbc0a32)

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-3f0-R9qsJuqmNGhT%2FScreen%20Shot%202019-01-24%20at%201.35.24%20PM.png?alt=media\&token=fed2c844-bef0-4630-a68a-ff9855a074c6)

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-41bKQbwYqmoPMQef%2FScreen%20Shot%202019-01-24%20at%201.37.01%20PM.png?alt=media\&token=adfdc087-f576-47ad-9f2e-fc0b39831204)

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-4Ey7jsZ17BjD6P5f%2FScreen%20Shot%202019-01-24%20at%201.37.56%20PM.png?alt=media\&token=8826b230-1e39-4cd7-a244-e4e0531503f7)

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-4yW2B8O3o-dTHnPE%2FScreen%20Shot%202019-01-24%20at%201.41.04%20PM.png?alt=media\&token=df356e49-5cfe-4068-843a-d652ef3f3b75)

## Calculations

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-EaSa6_CacoEDCdW0%2FScreen%20Shot%202019-01-24%20at%201.46.38%20PM.png?alt=media\&token=5f1fb5a0-b1d1-4b74-86da-6d7f20789ae3)

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-EfNgzl-2R0xj9LeE%2FScreen%20Shot%202019-01-24%20at%201.50.55%20PM.png?alt=media\&token=dc443457-683f-4824-9ef6-c5203ebd6ae3)

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-EmzjvxstBfhgQwSC%2FScreen%20Shot%202019-01-24%20at%201.52.45%20PM.png?alt=media\&token=1390f676-d98e-4bc8-a882-178abe087cf2)

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-Epsvcp4qXNLzD95X%2FScreen%20Shot%202019-01-24%20at%201.53.59%20PM.png?alt=media\&token=ccc4d78c-e615-44a9-8462-1bbfcf6552dd)

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-EygDG4QqiG3nnI1j%2FScreen%20Shot%202019-01-24%20at%201.56.28%20PM.png?alt=media\&token=17862d47-45ce-45b9-839e-5e71c1ce41ad)

![](https://3501392451-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LLZ89zzVxrdnG1RG6CA%2F-LX-3MuBgbBetnht0R_G%2F-LX-F0jMkvdkaHJ3Vq9K%2FScreen%20Shot%202019-01-24%20at%201.57.09%20PM.png?alt=media\&token=9236fd3d-5a84-4a65-9043-474d8d21a805)