95.6k views
0 votes
Find the derivative of the function using the definition of derivative. f(x) = 6 + x 1 − 6x f '(x) = State the domain of the function. (Enter your answer in interval notation.) State the domain of its derivative. (Enter your answer in interval notation.)

2 Answers

7 votes

Final answer:

The derivative of the corrected function f(x) = 6 - 5x is f'(x) = -5. The domain of both the function and its derivative is all real numbers, expressed in interval notation as (-∞, ∞).

Step-by-step explanation:

The question asks to find the derivative of the function f(x) = 6 + x - 6x using the definition of derivative and to state the domain of the function and its derivative. However, there seems to be a typo in the expression of the function. Assuming the correct expression of the function is f(x) = 6 + x - 6x, which simplifies to f(x) = 6 - 5x, let's compute the derivative:

The derivative of f(x) using the power rule is:

f'(x) = d/dx(6) - 5*d/dx(x) = 0 - 5 = -5

Since the derivative is a constant, the function is a linear function and its graph is a straight line. The domain of a linear function is all real numbers, so the domain of f(x) is (-∞, ∞). Similarly, the domain of its derivative f'(x) is also all real numbers: (-∞, ∞).

User JessieArr
by
5.1k points
0 votes

Answer:


f'(x)=(37)/((1-6x)^2)

Domain of f(x):
(-\infty,(1)/(6))\cup ((1)/(6),\infty).

Domain of f'(x):
Domain=(-\infty,(1)/(6))\cup ((1)/(6),\infty).

Step-by-step explanation:

Consider the given function


f(x)=(6+x)/(1-6x)

Domain of this function is all real numbers except those numbers for which denominator is equal to 0.


1-6x=0


1=6x

Divide both sides by 6.


(1)/(6)=x

The function f(x) is not defined for 1/6. So, the domain of the function f(x) is


Domain=(-\infty,(1)/(6))\cup ((1)/(6),\infty)

Find the derivative of the function using the definition of derivative.


f'(x)=lim_(x\rightarrow 0)(f(x+h)-f(x))/(h)


f'(x)=lim_(x\rightarrow 0)((6+(x+h))/(1-6(x+h))-(6+x)/(1-6x))/(h)


f'(x)=lim_(x\rightarrow 0)(1)/(h)((6+x+h)(1-6x)-(6+x)(1-6x-6h))/((1-6x-6h)(1-6x))


f'(x)=lim_(x\rightarrow 0)(1)/(h)((6+x)(1-6x)+h(1-6x)-(6+x)(1-6x)-(6+x)(-6h))/((1-6x-6h)(1-6x))


f'(x)=lim_(x\rightarrow 0)(h)/(h)(1-6x+36+6x)/((1-6x-6h)(1-6x))


f'(x)=lim_(x\rightarrow 0)(37)/((1-6x-6h)(1-6x))

Apply limit.


f'(x)=(37)/((1-6x-6(0))(1-6x))


f'(x)=(37)/((1-6x)^2)

The derivative of given function is
f'(x)=(37)/((1-6x)^2).


(1-6x)^2=0


1-6x=0


1=6x

Divide both sides by 6.


(1)/(6)=x

The function f'(x) is not defined for 1/6. So, the domain of the function f'(x) is


Domain=(-\infty,(1)/(6))\cup ((1)/(6),\infty).

User PretzelJesus
by
5.4k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.