The approximate rate of change in the number (in billions) of monthly text messages is given by the equation f prime (t )equals7.9tminus15.1 where t represents the number of years since 2000. In 2002 (tequals2) there were approximately 9.4 billion monthly text messages. Complete parts a. and b. below.

a. Find the function that gives the total number (in billions) of monthly text messages in year t.

b. According to this function, how many monthly text messages were there in 2009?

y = 3x+4

step-by-step explanation:

to find the slope

slope = (y2-y1)/ (x2-x1)

    = (-8-4)/ (-4-0)

    = -12/-4

  = 3

using the slope intercept form of a line

y= mx+b

we know the slope is 3

we know the y intercept is 4 ( the point where it crosses the y axis or x=0)

y = 3x+4

step-by-step explanation:

given expression is .

now we need to simplify the given expression .

we know that square root is equivalent to the power 1/2. so that means we can take half of the exponents to get the square root of given expression.

expanding that will give a very very large number so let's keep answer in exponent form.