Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

The derivative of a function 
f is given by 
f^(')(x)=ln |x|*x.
On which interval is the graph of 
f concave up?
Use a graphing calculator.
Choose 1 answer:
(A) 
-1 < x < 0 and 
x > 1
(B) 
x > 0
(C) 
x < 0
(D) 
x < -0.368 and 
x > 0.368
(E) All real numbers

The derivative of a function f f is given by f(x)=lnxx f^{\prime}(x)=\ln |x| \cdot x .\newlineOn which interval is the graph of f f concave up?\newlineUse a graphing calculator.\newlineChoose 11 answer:\newline(A) 1<x<0 -1<x<0 ="" and="" =""x="">1="" x="">1 \newline(B) x>0 \newline(C) x<0 \newline(D) x<-0.368 and x>0.368 \newline(E) All real numbers

Full solution

Q. The derivative of a function f f is given by f(x)=lnxx f^{\prime}(x)=\ln |x| \cdot x .\newlineOn which interval is the graph of f f concave up?\newlineUse a graphing calculator.\newlineChoose 11 answer:\newline(A) 1<x<0 -1<x<0 and x>1 x>1 \newline(B) x>0 x>0 \newline(C) x<0 x<0 \newline(D) x<0.368 x<-0.368 and x>0.368 x>0.368 \newline(E) All real numbers
  1. Calculate First Derivative: To determine where the graph of ff is concave up, we need to find the second derivative, f(x)f''(x), and look for where it is positive.\newlinef(x)=lnxxf'(x) = \ln|x|\cdot x\newlinef(x)=ddx(lnxx)f''(x) = \frac{d}{dx}(\ln|x|\cdot x)
  2. Apply Product Rule: Use the product rule for differentiation: uvuv' = u'v + uv'. Let u=lnxu = \ln|x| and v=xv = x. Then u=1xu' = \frac{1}{x} and v=1v' = 1. f(x)=(1x)x+lnx1f''(x) = \left(\frac{1}{x}\right)x + \ln|x|\cdot 1
  3. Simplify Second Derivative: Simplify the second derivative: f(x)=1+lnxf''(x) = 1 + \ln|x|
  4. Determine Positive Values: Find where f(x)f''(x) is positive: 1 + \ln|x| > 0 \ln|x| > -1
  5. Solve for x (x > 0): Solve for x in the inequality \ln|x| > -1. For x > 0: \ln(x) > -1 For x < 0: \ln(-x) > -1
  6. Solve for x x < 0: Exponentiate both sides of the inequalities to solve for x.\newlineFor x > 0: e^{\ln(x)} > e^{-1}, so x > \frac{1}{e}\newlineFor x < 0: e^{\ln(-x)} > e^{-1}, so -x > \frac{1}{e}, which means x < -\frac{1}{e}

More problems from Find derivatives of sine and cosine functions