Eric Nicholas K's answer to Sonia's Secondary 4 A Maths Singapore question.

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Eric Nicholas K
Eric Nicholas K's answer
2913 answers (Tutor Details)
1st
Differentiating e gives you e again. But there is a chain '-0.3t' to be differentiated.
Eric Nicholas K
Eric Nicholas K
4 months ago
(a) is simply solving an exponential equation for t.

(c) is setting t to a large number so e to the power of -0.3t is a very tiny number.