If f(x)=4arctan(7x), find f'(x). Find f'(4).

f'(x) = (4 arctan(7x))'

f'(x) = 4 (arctan(7x))'

By the chain rule,

f'(x) = 4/(1 + (7x)^2) * (7x)'

f'(x) = 28/(1 + 49x^2)

and hence

f'(4) = 28/(1 + 49*16) = 28/785

In case you're not sure about the derivative of arctan: If y = arctan(x), then x = tan(y). Differentiating both sides with respect to x gives

1 = sec^2y y' = (1 + tan^2y) y' = (1 + x^2) y'

==>  y' = 1/(1 + x^2)

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.

3, 12, 48, 384, 1536, 6144, 24576, 98304

step-by-step explanation:

just keep timing it by 4.