Determine which of the following constitutional instructions are formally codified within the primary boundary of Part IV (Directive Principles of State Policy):
1. The mandate requiring the state to ensure adequate facilities for primary education instruction in a minority demographic's mother-tongue.
2. The socio-economic directive instructing the state to actively promote cottage industries in rural areas.
3. The specific cultural directive mandating the widespread promotion and development of the Hindi language.
4. The economic imperative demanding the state secure equal pay for equal work for both men and women.