Given the model for the angle 𝐴 = (e^(-at)-e^(-bt))/(b-a) of a heavily damped swinging door, at what time 𝑡𝑀 is the amplitude the greatest?

Answer 1

Also: When 𝑏=𝑎 , the damping is said to be “critical"; how does 𝐴 then depend on 𝑡?

Both answers should be in terms of 𝑒, the variable 𝑡, and the parameter 𝑎 )

So lost, but would love to know how to do this.