What is the instantaneous rate of change for f(t)= sqrt (5t+1) when t=1?

1 Answer
Jul 21, 2016

(5sqrt6)/12

Explanation:

The color(blue)"instantaneous rate of change" is the value of f'(t) at t = 1.

differentiate f(t) using the color(blue)"chain rule and power rule"

f(t)=sqrt(5t+1)=(5t+1)^(1/2)

rArrf'(t)=1/2(5t+1)^(-1/2).d/dt(5t+1)

=5/2(5t+1)^(-1/2)=5/(2(5t+1)^(1/2))=5/(2sqrt(5t+1))

rArrf'(1)=5/(2sqrt6)=5/(2sqrt6)xxsqrt6/sqrt6=(5sqrt6)/12