Find the Exact Length of the Helix

Question

r→(t)=〈 4cos(1t/1), 4sin(1t/1), 3t 〉 for −4 ≤ t ≤ 8

Answer 1

in cylindrical have ∫√(r'²+r²θ'²+z'²)dt t from -4 to 8,,,r'=dr/dt, θ'=dθ/dt

is formula for curve length and limits given

helix is described in cylindrical as (4,t,3t) as (r,θ,z)

integral winds up just being ∫5dt from -4 to 8

=60