(a) Negative values for R have no physical significance, hence P is not plotted for negative values of R.
(b) determine the values in the table:
| R | 0 | 1 | 2 | 3 | 4 | 5 |
| P | 0 | 44.4 | 32.0 | 24.5 | 19.8 | 16.5 |
(c) Check what happens between R = 0 and R = 1 ie.
when R = 0.25, P = 44.4
R = 0.50, P = 50
R = 0.75, P = 48
(d) Conclusions:
(i) The maximum power of 50 W occurs for R = 0.5 W
(ii) P decreases as R increases beyond 0.5 W