The question is about differential physics (ODE, Integrals, derivatives and other similar things)

'the answer is alternative 5, but I don't know if it's correct'

A string with coefficient a =?21?? m/s length L = 4 m, has initial height distribution

given by function:

d (x) = 2x - 8x, 0 ? x ? 4,

At the exact moment time began to be measured, its speed had the same mathematical form

of the d (x) function. Obtaining the solution of the wave contour problem, answer what is the ratio between

b (n) and a (n):

\f