For , it is given that when . Find at that…

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

Problem

For

y=5x^{3}-2x

, it is given that

\displaystyle \frac{dy}{dt}=6\,\text{cm/s}

when

x=2\,\text{cm}

. Find

\displaystyle \frac{dx}{dt}

at that instant. (a)

\displaystyle \frac{29}{3}\,\text{cm/s}

(b)

\displaystyle \frac{3}{29}\,\text{cm/s}

(c)

\displaystyle -\frac{3}{29}\,\text{cm/s}

(d)

\displaystyle \frac{3}{14}\,\text{cm/s}