f(x) problem

[Dreven]

Problem: Let f(x)=x/(x-1)
Find and simplify
f(1/t)

I don't remember what to do with fractions. Could someone show me a step by step work through, with the fractions explained? Thank you.

 

[Loren]

Is there a typo? You have defined f(x) but not F(x).

 

[A_G]

Let f(x)=x/(x-1)

To find f(1/t) simply replace all 'x' with '1/t'
So f(1/t) = (1/t)/(1/t - 1) = (1/t) ÷ (1-t)/t

Let me know if you can do it from here

 

[mmm4444bot]

… I don't remember what to do with fractions …

If this is the case, then, after you digest Anirban's steps, I'm guessing that you'll probably need to remember the following important rule for simplifying expressions which contain division by a fraction.

(A/B) / (C/D) = A/B * D/C

In other words, change from dividing by a fraction to multiplying by it's reciprocal, instead.

 

[PAULK]

Problem: Let f(x)=x/(x-1)
Find and simplify
f(1/t)

I don't remember what to do with fractions. Could someone show me a step by step work through, with the fractions explained? Thank you.

What you do with fractions is a simple issue. Here it's 'what do you do with function notation?' The answer is USE PARENTHESES:
(1/t)
f(1/t) = -----------
(1/t) - 1

NOW you can worry about fractions. Ask the right questions:

1. What is it?
Answer: A complex fraction. (A fraction that contains fractions.)
2. What do I do?
Answer: Clear fractions, multiplying by the LCD.
3. What's the LCD?
Answer: t.

Multiply every term by t. Poblem disappears.