On the interval while

MATHEMATICS · Single correct · A Level · Mathematics · Differentiation · Differentiation

Problem

On the interval

2<t<5

, a particle moves so that

\dfrac{dy}{dt}>0

while

\dfrac{dx}{dt}<0

. Which statement correctly describes the behavior of

y

with respect to

x

on that interval? (a)

y

increases as

x

decreases, and

\dfrac{dy}{dx}

is positive. (b) Both

y

and

x

increase, so

\dfrac{dy}{dx}

is positive. (c)

y

increases as

x

decreases, and

\dfrac{dy}{dx}

is negative. (d)

y

decreases as

x

decreases, so

\dfrac{dy}{dx}

is positive.