A Point Is Moving Along the Graph of the Function $y = 9 x ^ { 2 } + 4$

Multiple Choice

A point is moving along the graph of the function $y = 9 x ^ { 2 } + 4$ such that $\frac { d x } { d t } = 3$ centimeters per second. Find dy/dt for the given values of x. (a) $x = 4~~~~~~~~~~~~~~~~~~~~~~~~~~$ (b) $x = 7$

A) $\frac { d y } { d t } = 4$ $\frac { d y } { d t } = 378$
B) $\frac { d y } { d t } = 216$ $\frac { d y } { d t } = 378$
C) $\frac { d y } { d t } = 378$ $\frac { d y } { d t } = 216$
D) $\frac { d y } { d t } = 7$ $\frac { d y } { d t } = - 216$
E) $\frac { d y } { d t } = 7$ $\frac { d y } { d t } = 378$