1. How does one obtain Eq. IX-5 or IX-6 from Eq. 9.3-8?
![1245_b6f1e2c8-bda8-41b3-92b2-7d18b055579d.png](https://secure.tutorsglobe.com/CMSImages/1245_b6f1e2c8-bda8-41b3-92b2-7d18b055579d.png)
![1451_069c74ec-2317-4c6d-a879-7d9e49c22c84.png](https://secure.tutorsglobe.com/CMSImages/1451_069c74ec-2317-4c6d-a879-7d9e49c22c84.png)
![307_dd5fa60b-0b10-429d-947a-1c7b28124636.png](https://secure.tutorsglobe.com/CMSImages/307_dd5fa60b-0b10-429d-947a-1c7b28124636.png)
2. Recalculate the reduction in radiation loss for the model shown in Fig. IX.4. There are two view factors to be determined; use your intuition to obtain both of them. Assume that the rock slab stretches to infinity in both directions.
![1794_66efbb71-4741-4d8f-9e49-13bbc467ee26.png](https://secure.tutorsglobe.com/CMSImages/1794_66efbb71-4741-4d8f-9e49-13bbc467ee26.png)