Integration question (1 Viewer)

[Yoko Hono]

In the Excel HSC Maths 2U text book, there is a question which I just can't figure out.

3
S 2 + 5x dx
1 x^3


The worked answer in the back of the book is:

= 3
S 2 + 5x dx
1 x^3 x^3

=2
S 2x^-3 + 5x^-2 dx
1


Then they solve this.

I get how they have integrated it but I don't get why it has changed

from 3 to 2
S S
1 1

 

[Kulazzi]

I don't think it should've changed. It should've stayed 3~1. They may be wrong. I believe it should still be 3~1.

 

[*ashlea*]

yeah i agree.. its probly just a typo... did they sub in 2 to get the answer? cos then its wrong.. if u get the same answer as them subbing in 3 then its definately a typo..
it shouldn't change from 3 to 2.

 

[Yoko Hono]

Yeah, they subbed in 2 to get the answer so I reckon its just a mistake in the book. Thanks for that. I wasn't sure whether I was doing it wrong or not.