How do you differentiate (t^2+2)/(6t-3)^7?

1 Answer
Jun 2, 2015

We must use the quotient rule, which states that

Be y=f(x)/g(x), then (dy)/(dx)=(f'(x)g(x)-f(x)g'(x))/(g(x))^2

Now, before starting, we can acknowledge all our four needed functions:

  • f(t)=t^2+2
  • f'(t)=2t

  • g(t)=(6t-3)^7

  • g'(t) demands chain rule, which states that (dy)/(dx)=(dy)/(du)(du)/(dx), so g'(t)=(7u^6)*6=color(green)(42(6t-3)^6)

Thus,

(dy)/(dt)=(2t(6t-3)^7-(t^2+2)(42(6t-3)^6))/(6t-3)^14=

=(2tcancel((6t-3)^7))/(6t-3)^(cancel(14)7)-((t^2+2)*42cancel((6t-3)^6))/(6t-3)^(cancel(14)8

Considering (6t-3)^8 our l.c.d.:

(2t(6t-3)-42(t^2+2))/(6t-3)^8=(12t^2-6t-42t^2-84)/(6t-3)^8=color(Green)((-30t^2-6t-84)/(6t-3)^8)