Solution

ID: past-exam-of-the-mphil-in-nuclear-energy-course-of-the-university-of-cambridge/2021/paper-ne1/2/f/i/solution

Differentiating the supplied relation gives
Thus the tangent approximation is and
It is about longer than and therefore predicts slower growth. For this positive step it is not conservative as a growth-rate estimate. The local expansion needs ; here the actual ratio is approximately , so its error is appreciable.

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