Mathematical Methods — Question 9

QCAA 2024, Paper 2 · 1 mark

Q9 · 2024 · Technology-activeSimple familiar1 mark

QUESTION 9

It is known that

f'(x)=0

and

f''(x)<0

for one of the labelled points on the graph of

f(x)

. Which point matches this description?

(A)

P

(B)

Q

(C)

R

(D)

S

ABCD

WORKED SOLUTION

1 mark

ANSWER

C —

R

Worked solution

f'(x)=0

requires a stationary point and

f''(x)<0

requires the graph to be concave down there, i.e. a local maximum. The labelled point with these properties is

R

, so option C.

Selects option C.

[1 mark]

Worked explanation by QCE Vault; correct option verified against the QCAA answer key.