Question

The voltage in a circuit is given by the formula V = 16t3 - 79t. Find the values for t for which V is a maximum or a minimum.

larger t in seconds =
smaller t in seconds =

My Answer:

V=16t^3-79t
V'=48t^2-79
0=48t^2-79
Sq root of 1.645833 = t
1.2829= t

V''=96t positive therefore a min

Larger t = 1.2829
smaller t = -1.2829


Can you please confirm this is correct.

Answer 1

looks good to me, but I wonder whether negative values of t make sense ...

Answer 2

Thanks Steve.