Richard P. answered • 07/03/20

PhD in Physics with 10+ years tutoring experience in STEM subjects

A sinusoid of the form: a cos(θ) + b sin(θ) can be rewritten as

A cos( θ - φ) where A = sqrt( a^{2} + b^{2} ) and φ = arctan( b/a)

For this problem a = 1 and b = sqrt(5) , so A = sqrt(6)

Therefore the maximum current will be sqrt(6) and the minimum - sqrt(6)

Of course there are time values for which the current is zero.