Answer with Explanation:
We are given that the mathematical form of wave
a.We have to find the speed of propagation of this wave
In given mathematical form
k=Wave number
=Angular frequency
A=Amplitude
We know that
Speed of propagation of the wave=
b.Differentiate w.r.r t
The velocity 
of a point on the string as a function of x and t is given by
Solar energy, wind energy, hydro energy
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-- Resistance can be useful among the population of a repressive government.
Although it can be dangerous for those who resist, it can also exert pressure
against the regime to alter its repressive practices.
-- Resistance can also be useful in electronic circuits. "Lumped" components with
known numerical values of resistance are used to divide voltage, limit current, and
dissipate controlled amounts of electrical energy.
