Thread: Help Desperately Needed (chain rule)

Working with the chain rule. Have two sets of problems, and I have no idea how to even get started. VERY confused/frustrated. Here are my two problem sets:

Code:

Suppose k '(1) = 4. 

(a) If f(x) = k(7x), find f '(1/7).
f '(1/7)=

(b) If g(x) = k(x+ 6), find g '(-5).
g '(-5) =

(c) If h(x) = k(x / 11), find h '(11).
h '(11) =

and

Code:

Suppose f(2) = 4 and f '(2) = 7. Find the derivatives 
of the following functions. 

(a) g(x) = sqrt(f(x)) 
g '(2)= 

(b) h(x) = 1/f(x) 
h '(2)=

If anyone can help me out it would be greatly appreciated. I have to turn this in by 11pm.

Originally Posted by keyweez360

Working with the chain rule. Have two sets of problems, and I have no idea how to even get started. VERY confused/frustrated. Here are my two problem sets:

Code:

Suppose k '(1) = 4. 

(a) If f(x) = k(7x), find f '(1/7).
f '(1/7)=

(b) If g(x) = k(x+ 6), find g '(-5).
g '(-5) =

(c) If h(x) = k(x / 11), find h '(11).
h '(11) =

and

Code:

Suppose f(2) = 4 and f '(2) = 7. Find the derivatives 
of the following functions. 

(a) g(x) = sqrt(f(x)) 
g '(2)= 

(b) h(x) = 1/f(x) 
h '(2)=

If anyone can help me out it would be greatly appreciated. I have to turn this in by 11pm.

Chain rule: if then .

I'll do Q1 (a):

.

Therefore .


As for Q2:

Again using the chain rule:

(a) .

(b) .

Fantastic!