Answer:
the required equation is; y = 21 sin(πt/6)
Step-by-step explanation:
Given the data in the question;
Water rises above sea level = 21 ft
Water drops below sea level = 21 ft
so
maximum = 21 ft and also
minimum = 21 ft
Amplitude = ( maximum + minimum ) / 2
Amplitude = ( 21 + 21 ) / 2
Amplitude = ( 21 + 21 ) / 2 = 42/2 = 21 ft
Period = 12 hours
and we know that; period = 2π/b
so
12 = 2π/b
12b = 2π
b = 2π / 12
b = π/6
Standard equation for simple harmonic is; y = asin(bt)
we substitute
y = 21 sin(πt/6)
Hence the required equation is; y = 21 sin(πt/6)
Yes, 3 yards is bigger than 21 feet because there are 3 feet in a yard.
Reciprocal means invert it . for eg- the reciprocal of 1/2 is 2/1 and of 4/7 is7/4.
B10/36 i think, if its not what youre looking for let me know