The frequency of a hum that is generated by an engine is 270 hz. It starts at zero, which function would best describe the frequency over time

our function is:

f(x) = A*sin(2*pi*270s*x)

Step-by-step explanation:

We have that the frequency of a given engine is 270 hz, it starts at 0, so we may represent this with a sin function (because sin(0) = 0)

Then we could use the function

f(x) = A*sin(c*x)

A is the maximum intensity of the hum, and c depends on te frequency, we know that the period of a sin function is 2pi, then:

f = 270/s

T = 1/270s

c*1/270s = 2pi

c = 2*pi*270s

Then our function is:

f(x) = A*sin(2*pi*270s*x)

-13

step-by-step explanation:

f(x)=2x-5 for f(-4)

f(-4)   means let x=-4

f(-4) = 2(-4) -5

f(-4) =-8-5

      = -13