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.

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

Thanks Steve.

Your calculations are not correct. Let me guide you through the correct steps to find the values of t for which V is a maximum or minimum.

Given the equation V = 16t^3 - 79t, we need to find the critical points by setting the derivative V' equal to zero.

Step 1: Find the derivative of V with respect to t:

V' = dV/dt = 48t^2 - 79

Step 2: Set V' equal to zero and solve for t:

48t^2 - 79 = 0

Step 3: Solve the quadratic equation:

48t^2 = 79
t^2 = 79/48
t = ±sqrt(79/48)

Step 4: Simplify the square root and calculate the approximate values of t:

t ≈ ± 1.1087

Therefore, the approximate values for t when V is a maximum or minimum are t ≈ 1.1087 and t ≈ -1.1087.

To summarize:

Larger t in seconds ≈ 1.1087
Smaller t in seconds ≈ -1.1087

Please note that the values provided are approximate, as we rounded the square root.