The general form of a sine function is:y=asin(bx+c)where a is the amplitude, b is the coefficient of the angle, and c is the phase shift.To find the period of the function, we have to divide the regular period of a sine function, which is 2π, by the coefficient of the angle.Therefore, the period of the above general sine function would be:
b
2π
.
In this problem, the period is given as T=10. This means:
b
2π
=10
2π=10b
b=
5
π
If we assume there is no phase shift. i.e. c=0 then our sine function would be:
y=0.75sin(
5
π
x)
y(4)=0.75sin(
5
π
(4))
y(4)=0.75sin(
5
4π
)=0.75(0.044)=0.033