## Homework Statement

Calculus Derivative help?
when x = 0, f=2, f '=1, g=5, g '= -4
when x = 1, f=3, f '=2, g=3, g '= -3
when x = 2, f=5, f '=3, g=1, g '= -2
when x = 3, f=10, f '=4, g=0, g '= -1
based on the above table, if a = f +2g, then a'(3) =?

## Homework Equations

if a = f +2g, then a'(3) =?

## The Attempt at a Solution

a=f'+0(g')
a'(3)=f'3+0
a'(3)=4????

I don't understand what the problem is =(

NascentOxygen
Staff Emeritus
based on the above table, if a = f +2g, then a'(3) =?
Does the textbook give you the correct answer?

vela
Staff Emeritus
Homework Helper

## Homework Statement

Calculus Derivative help?
when x = 0, f=2, f '=1, g=5, g '= -4
when x = 1, f=3, f '=2, g=3, g '= -3
when x = 2, f=5, f '=3, g=1, g '= -2
when x = 3, f=10, f '=4, g=0, g '= -1
based on the above table, if a = f +2g, then a'(3) =?

## Homework Equations

if a = f +2g, then a'(3) =?

## The Attempt at a Solution

a=f'+0(g')
You didn't differentiate this correctly. You may want to review the properties of differentiation.
a'(3)=f'3+0
a'(3)=4????

## Homework Statement

Calculus Derivative help?
when x = 0, f=2, f '=1, g=5, g '= -4
when x = 1, f=3, f '=2, g=3, g '= -3
when x = 2, f=5, f '=3, g=1, g '= -2
when x = 3, f=10, f '=4, g=0, g '= -1
based on the above table, if a = f +2g, then a'(3) =?

## Homework Equations

if a = f +2g, then a'(3) =?

## The Attempt at a Solution

a=f'+0(g')
a'(3)=f'3+0
a'(3)=4????

can anyone just please give me the steps on how to do it and just be direct

a = f + 2g really means that a at 3 will equal f at 3 added to twice the value of g at 3. The latter information is given you in your table; just do the addition.

But how to calculate the derivative of a? That's where the point of the whole problem comes into play. The goal of the problem is to get you to think about one of the rules of derivatives. What rule have you learned that allows you to calculate the derivative of a sum of functions of which you already know the derivatives?

HallsofIvy
Homework Helper

## Homework Statement

Calculus Derivative help?
when x = 0, f=2, f '=1, g=5, g '= -4
when x = 1, f=3, f '=2, g=3, g '= -3
when x = 2, f=5, f '=3, g=1, g '= -2
when x = 3, f=10, f '=4, g=0, g '= -1
based on the above table, if a = f +2g, then a'(3) =?

## Homework Equations

A very relevant equation is "(af(x)+ bg(x))'= af'(x)+ bg'(x)"

if a = f +2g, then a'(3) =?

## The Attempt at a Solution

a=f'+0(g')
Where did this "0" come from? a'(3)= f'(3)+ 2g'(3)

a'(3)=f'3+0
a'(3)=4????

can anyone just please give me the steps on how to do it and just be direct

Mark44
Mentor
can anyone just please give me the steps on how to do it and just be direct
That's not how it works here at Physics Forums. We provide help so that you can do a problem, but we don't do the work for you.

eumyang
Homework Helper
That's not how it works here at Physics Forums. We provide help so that you can do a problem, but we don't do the work for you.
To the OP: also, stop posting the same question in multiple threads. I believe that's also against the forum rules.

berkeman
Mentor

NascentOxygen
Staff Emeritus