(a) Negative values for R have no physical significance, hence P is not plotted for negative values of R.

(b) Draw up a table of values:

 R 0 1 2 3 4 5 P 0 44.4 32 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

Note the axes are labelled with R (resistance) and P (power).

(d) Conclusions:

(i) The maximum power of 50\ "W" occurs when resistance R = 0.5\ "W"

(ii) P decreases as R increases beyond 0.5\ "W"

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