Q106 · Practice questionComplex unfamiliar6 marks
QUESTION 106 (6 marks)
A curve satisfies
a)[3 marks]
Show that its solution can be written implicitly as
b)[2 marks]
Use technology to determine when , to four decimal places.
c)[1 mark]
Determine the gradient at that point, to four decimal places.
WORKED SOLUTION
6 marksPractice marking scheme
ANSWER
(a) ; (b) ; (c) .
Worked solution
(a) Separate and integrate: The initial condition gives , establishing the required expression.
(b) At , solve . Numerical solution gives . The left side is strictly increasing, so this real root is unique.
(c) Substituting the unrounded root into the differential equation gives
Separates variables.
Integrates correctly.
Applies the initial condition.
Determines the numerical root.
Determines the gradient.
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