Advanced Calc( Derivatives)

In summary, the differential function f satisfies the conditions f'(0) is not equal to zero for all a,b (real numbers) and f(a+b) = f(a)f(b). Using these conditions, it can be shown that f'(x) = f'(x)f(x) and that f(0) = 1. Additionally, considering f(2x) = f(x+x) = f(x)f(x) = f(x)^2 provides further insight into the behavior of the function.
  • #1
chief12
11
0

Homework Statement


function f is differential when x=0,
f'(0) is not equal to zero for all a,b(real Numbers)
f(a+b) = f(a)f(b)

show f'(x) = f'(x)f(x)


Homework Equations





The Attempt at a Solution


f(a+b) = f(a)f(b) for all a,b(real numbers)
f(0), a+b=0
then f(0) = 1

lim x-->0 f(x) = f(0) = 1

then i get stuck
 
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  • #2
chief12 said:

Homework Statement


function f is differential when x=0,
f'(0) is not equal to zero for all a,b(real Numbers)
f(a+b) = f(a)f(b)

show f'(x) = f'(x)f(x)

that would imply f(x) = 1 for all x... which then gives f'(x) = f'(0) = 0
also f'(0) is not equal to zero for all a,b,... does this mean only for a=-b?

are you sure this is how the question was written? try and write thinsg exactly as they are given...
 
Last edited:
  • #3
now guessing at what teh question actually asked... i would start by considering
f(x+0) = f(x) = f(x)f(0)
this shows f(0) = 1
 
  • #4
then consider f(2x)
 

What is the definition of a derivative?

A derivative is a mathematical concept that represents the rate of change of one quantity with respect to another. It is defined as the slope of a tangent line to a curve at a specific point.

How do you find the derivative of a function?

To find the derivative of a function, you can use the rules of differentiation, such as the power rule, product rule, quotient rule, and chain rule. Alternatively, you can also use the definition of a derivative to calculate it.

What is the purpose of finding derivatives?

Finding derivatives is important in mathematics because it allows us to understand the behavior of a function, such as its rate of change, concavity, and critical points. It also has many applications in fields such as physics, engineering, and economics.

What is the difference between a derivative and a differential?

A derivative is a function that represents the rate of change of another function, while a differential is an infinitesimal change in a variable. In other words, a derivative is a concept, while a differential is a quantity.

Can derivatives be applied to multivariable functions?

Yes, derivatives can be extended to multivariable functions, resulting in partial derivatives. These represent the rate of change of one variable with respect to another, while holding all other variables constant. Higher order derivatives, such as second or third derivatives, can also be calculated for multivariable functions.

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