# Derivation of dz=da\* g'(z) ? or dz= a- y? how is derivation of dz\[1\] and dz\[2\] different?

**URL:** <https://community.deeplearning.ai/t/derivation-of-dz-da-g-z-or-dz-a-y-how-is-derivation-of-dz-1-and-dz-2-different/347759>\
**Category:** Neural Networks and Deep Learning\
**Tags:** coursera-platform\
**Created:** [May 31, 2023, 2:41pm UTC](https://community.deeplearning.ai/t/derivation-of-dz-da-g-z-or-dz-a-y-how-is-derivation-of-dz-1-and-dz-2-different/347759 "2023-05-31T14:41:52Z")\
**Posts on this page:** 1\
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**Author:** ![saifkhanengr](https://sea1.discourse-cdn.com/dlai/user_avatar/community.deeplearning.ai/saifkhanengr/32/152858_2.png) [@saifkhanengr](https://community.deeplearning.ai/u/saifkhanengr)\
**Post date:** [June 1, 2023, 5:29am UTC](https://community.deeplearning.ai/t/derivation-of-dz-da-g-z-or-dz-a-y-how-is-derivation-of-dz-1-and-dz-2-different/347759/6 "2023-06-01T05:29:52Z")

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> [@Rohan\_Devaki](#):
>
> dz[1] = w[1]T \* dz[2] \* da[1] \* g’(z[1])
> 
> is written from the sirs classes, as i have written my steps above, i am not able to get this as a conclusion

From which class do you get this? Can you share a link with us?

Regarding the explanation of the Chain Rule, it just needs your familiarity with Calculus. If you are not familiar with it, check this [guide](https://community.deeplearning.ai/t/course-1-week-3-backpropagation-intuition/7979/2) by Paul which refers to some other links.

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