Question

Evaluate:
I will post problem

Answer 1

\[\int\limits_{-1}^{3} (3x-5)^4\]

Answer 2

I get to 1/24(3x-5)^8

Answer 3

this is before I substitute

Answer 4

1st I get u=3x-5
3dc= 1/3 du

Answer 5

the dc is dx

Answer 6

Where are you getting 1/24 and ^8?

Answer 7

never mind the 1/24 and 1/8
I looked at something else as I was writing. I will redo this one first

Answer 8

how about 1/15(3x-5)^5
does that look better? I really unsure about what I am doing.

Answer 9

this answer is before I substitute

Answer 10

Yeah, that looks right

Answer 11

\[\int\limits (3x-5)^4 \, dx = -\frac{1}{15} (5-3 x)^5 \]
\[\int\limits_{-1}^3 (3x-5)^4 \, dx= \frac{11264}{5} \]
\[\left(-\frac{1}{15} (5-3 x)^5\text{/.}x\to 3\right)-\left(-\frac{1}{15} (5-3 x)^5\text{/.}x\to -1\right)=\frac{11264}{5} \]

Answer 12

Good example to follow. (You miswrote the problem.

Answer 13

why did you switch to 5-3x and not keep it as 3x-5

Answer 14

typo

Answer 15

where did I miswrite the problem? The only thing I left off was the dx at the end

Answer 16

Not you Robto

Answer 17

ok

Answer 18

now I think I should have

1/15(3(3)-5)^4 - 1/15(3(-1)-5)^4

1/15(16) - 1/15(4096)

is that correct so far??

Answer 19

Processing chaguanas's statement.

Answer 20

?

Answer 21

are you still there

Answer 22

what's wrong?

Answer 23

did you see the last post I made
What I think I should have after substitution

Answer 24

Your process is right. I don't have to check the minutia, that part is all arithmetic. Put you are inputting -1. The writing is very small on the original problem is the low end point 1 or -1?

Answer 25

-1

I was just checking because the problem asks to express as a decimal, approximate to one decimal place. After I do the problem I get -272. I thought I might be doing it wrong.

Answer 26

Approximate to one decimal place, tells you nothing of the answer. It is instructions on how to write your answer. Assuming that is the right answer, to one decimal place is -272.0

Answer 27

ok I was just thinking the answer would be different

Answer 28

mom:
Way to go mom. No ambiguity in your problem statement.

chaguanas:
\[-\frac{1}{15} (5-3 x)^5 = \frac{1}{15} (3 x-5)^5 \]
I am using the Mathematica program, version 8, to solve this and that on this web site. With Mathematica at my disposal I am not about to solve anything related to mathematics with pencil and paper.

Mathematica has been in development for some years now. In the early years the developers made some decisions regarding the input language construction and what they would deliver for output forms (answers). One thing that "does not look right" is that their polynomial answers are printed with the exponents, in the exponential terms, ordered low to high, not high to low as presented on school chalk/white boards. At first that was annoying for me but soon one adjusts and excepts their formulations. Probably the tendency for some inexperienced math students is to conclude that because a polynomial as written "doesn't look right", it must be inherently wrong and conveys the wrong intent.