Question

the equation that models the height above or below the equilibrium in inches h of a spring over time in seconds t is h=-30cos(2pi/5t) at which times will the spring be at a height of 20 inches above equilibrium select two answers

Answer 1

Answer:

$B,\text{ C}$

Explanation:

Here, we want to get the times at which the spring will be at a height of 20 inches above equilibrium

A way to solve this is to plot the graph of the given function

We have the plot as shown below:

Now, we proceed to look at the t-values where we have h at 20

Looking at the plot, we have the correct answer choice at t = 3.2 seconds and t = 1.8 seconds