Help with Test Q: What is fg'(3)?

  • Thread starter Thread starter JoshuaC
  • Start date Start date
  • Tags Tags
    Test
Click For Summary
SUMMARY

The discussion centers on calculating the derivative of the product of two functions, specifically fg'(3), given the values f(3)=5, g(3)=-4, f'(3)=1.1, and g'(3)=0.7. The correct approach involves applying the product rule, expressed as (fg)' = fg' + gf'. By substituting the provided values, the answer is determined to be -0.4, corresponding to choice d). The forum emphasizes the importance of showing work when seeking homework assistance.

PREREQUISITES
  • Understanding of calculus concepts, specifically the product rule for derivatives.
  • Familiarity with function notation and evaluation at specific points.
  • Basic knowledge of derivatives and their interpretation.
  • Ability to perform arithmetic operations with real numbers.
NEXT STEPS
  • Study the product rule in calculus to solidify understanding of derivative calculations.
  • Practice evaluating derivatives of composite functions using examples.
  • Explore real-world applications of derivatives in physics and engineering.
  • Review common mistakes in derivative calculations to avoid errors in future problems.
USEFUL FOR

Students studying calculus, particularly those preparing for tests involving derivatives, as well as educators looking for examples of product rule applications in homework discussions.

JoshuaC
Messages
3
Reaction score
0
Hello!

I have a question from a test that I wasn't sure about, so I guessed.

The question is:

f(3)= 5
g(3)= -4
f'(3)= 1.1
g'(3)= .7

What is fg'(3)

Answer choices: a) .9 b) .4 c) -.9 d) -.4

Does anyone know the answer? And how did you get it?

Help would be much appreciated. Thanks!
 
Last edited:
Physics news on Phys.org
Do you mean (fg)'(3)?

Also, homework help forum.

Also (fg)'=fg'+gf'
So just plug in what they gave.
 
JoshuaC said:
Hello!

I have a question from a test that I wasn't sure about, so I guessed.

The question is:

f(3)= 5
g(3)= -4
f'(3)= 1.1
g'(3)= .7

What is fg'(3)

Answer choices: a) .9 b) .4 c) -.9 d) -.4

Does anyone know the answer? And how did you get it?

Help would be much appreciated. Thanks!

You are required to show some effort at answering the question when posting schoolwork questions. Please use the hints from johnqwertyful and show your work...
 

Similar threads

Prove that f is a homeomorphism iff g is continuous, fg=1 and gf=1
  • · Replies 5 ·
Replies
5
Views
2K
Prove ##|\{ q\in\mathbb{Q}: q>0 \} |=|\mathbb{N}|##.
  • · Replies 3 ·
Replies
3
Views
2K
Unsolvable max/min of surface with constraint
  • · Replies 9 ·
Replies
9
Views
2K
Find the two points on the curve that share a tangent line
  • · Replies 9 ·
Replies
9
Views
2K
Determine limits of integration in double integral change of variables
  • · Replies 2 ·
Replies
2
Views
2K
Does the series converge using the integral test?
  • · Replies 16 ·
Replies
16
Views
4K
Prove limit comparison test for Integrals
  • · Replies 2 ·
Replies
2
Views
2K
Finding large prime factors (number theory)
  • · Replies 2 ·
Replies
2
Views
1K
Does there exist a 2x2 non-singular matrix with only one 1d eigenspace?
  • · Replies 2 ·
Replies
2
Views
2K
Calculus Derivatives: Find (a-d) at 3
  • · Replies 5 ·
Replies
5
Views
2K