Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

$$\left.\left(\frac{2x^3}{3} - 4x^2 + 10x\right) \right|_1^3 = 12 - 20/3$$

I guess my first question would be what is the meaning of the line in this equation. I was under the impression it is meant to represent a range of x values. However I'm not sure how both sides are equal or how one would go about solving this.

share|improve this question
    
@Peter Tamaroff. I thank you with all my heart. –  Michael Gruber Sep 7 '12 at 0:27
    
$ f(x) |_{x_0}^{x_1} = f(x_1) - f(x_0) $ –  user2468 Sep 7 '12 at 0:31
add comment

2 Answers 2

up vote 3 down vote accepted

This is typically used when solving definite integrals.

It means $f(3) - f(1)$, so:

$f(3) = (2/3)*27 - 4(9) + 10(3) = 12$, and

$f(1) = (2/3)*1 -4(1) + 10(1) = 20/3$

therefore $(12 - 20/3)$.

Note: be careful writing $2/3x^3$ because it could be incorrectly interpreted.

share|improve this answer
add comment

$$f(x)\bigr|^b_a$$ is notation for $f(b)-f(a)$.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.