1.52: Product rule and related rates

0606/12/O/N/19 — Question 7 · 7 marks

It is given that y=(1+ex2)(x+5)y = (1 + \mathrm{e}^{x^{2}})(x + 5).
(i)
Find dydx\dfrac{\mathrm{d}y}{\mathrm{d}x}.
[3]
(ii)
Find the approximate change in yy as xx increases from 0.50.5 to 0.5+p0.5 + p, where pp is small.
[2]
(iii)
Given that yy is increasing at a rate of 22 units per second when x=0.5x = 0.5, find the corresponding rate of change in xx.
[2]