If f(x)=5x-2 and g(x)= cubed sqrt of x ( or x^(1/3)), evaluate (fog)(-8)

Expert Answers

An illustration of the letter 'A' in a speech bubbles
Given that: f(x) = 5x-2. g(x) = (x^1/30 We need to find fog(x) First we will rewrite fog(x) as follows: fog(x) = f(g(x)) We will substitute with g(x) = x^1/3 ==> fog(x) = f(x^1/3) Now we will substitute with x^1/3 in f(x) ==> fog(x) = 5(x^1/3) -2 Now we will substitute with x=-8. ==> fog(x) = 5(-8^1/3) -2 = 5*-2 -2 = -10 -2 = -12 ==> fog(-8) = -12.
Approved by eNotes Editorial Team

Posted on

An illustration of the letter 'A' in a speech bubbles

We have f(x) = 5x - 2 and g(x) = x^(1/3) [ I have assumed by cubed sqrt you mean raised to the power (1/3)]

We have to find fog( - 8)

fog(x) = f(g(x)) = f( x^(1/3))

=5 * x^(1/3) - 2

For x = -8

fog(-8) = 5*(-8)^(1/3) - 2

=> 5* (-2) - 2

=> -10 - 2

=> -12

The required result is -12

Approved by eNotes Editorial Team

Posted on

Soaring plane image

We’ll help your grades soar

Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.

  • 30,000+ book summaries
  • 20% study tools discount
  • Ad-free content
  • PDF downloads
  • 300,000+ answers
  • 5-star customer support
Start your 48-Hour Free Trial