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Date November 2020 Marks available 3 Reference code 20N.2.AHL.TZ0.H_8
Level Additional Higher Level Paper Paper 2 Time zone Time zone 0
Command term Find Question number H_8 Adapted from N/A

Question

A small bead is free to move along a smooth wire in the shape of the curve y=103-2e-0.5xx0.

Find an expression for dydx.

[3]
a.

At the point on the curve where x=4, it is given that dydt=-0.1m s-1

Find the value of dxdt at this exact same instant.

[3]
b.

Markscheme

* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.

valid attempt to use chain rule or quotient rule       (M1)

dydx=-10e-0.5x3-2e-0.5x2  OR   dydx=-10e-0.5x3-2e-0.5x-2      A1A1


[3 marks]


Note: Award A1 for numerator and A1 for denominator, or A1 for each part if the second alternative given.

a.

valid attempt to use chain rule eg  dydt=dydx×dxdt      (M1)

dxdt=-0.1÷-10e-23-2e-22 =-0.1÷-0.181676  or equivalent      (A1)

=0.550428

dxdt=0.550 ms-1       A1


[3 marks]

b.

Examiners report

[N/A]
a.
[N/A]
b.

Syllabus sections

Topic 5 —Calculus » SL 5.6—Differentiating polynomials n E Q. Chain, product and quotient rules
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Topic 5 —Calculus

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