Maths Question

[Opara]

Hi, i'm having a bit of trouble with some homework, I can do the question but i'm having trouble simplifying the answer down.If you see the picture it is an example question, and shows the format of the answer required.I have done the differentiating part but it's the simplifying under the "It then follows from the product ....."





Any help gratefully received

[tank slapper]

Opara said:

Hi, i'm having a bit of trouble with some homework, I can do the question but i'm having trouble simplifying the answer down.If you see the picture it is an example question, and shows the format of the answer required.I have done the differentiating part but it's the simplifying under the "It then follows from the product ....."





Any help gratefully received

They are factorising. To make it a bit clearer, If you replace (2x+12) by a and (2x-1) by b, then the first line is:

a^6 8b^3 + b^4 12a^5

a^5 and b^3 are common factors, so you can rewrite it as:

a^5 b^3 (8a + 12b)

If you substitute the values for a and b, then you can see it is the second line.

The third line, they have taken the 2 out of the first bracket, which means it is also raised to the power 5, and for the last bracket they have simply expanded the inner two brackets.

You should be able to see how they have arrived at the last line from that.

Edited by tank slapper on Tuesday 5th November 20:18

[Opara]

Excellent stuff, swapping for a and b made it a lot clearer.I missed the second set of brackets so I wasn't seeing the factorisation.

Thanks again

[Simpo Two]

Sometimes it is refreshing to be completely baffled.

I don't even know what ^ means

[tank slapper]

It's just to indicate raised to the power of as there isn't a superscript format code on PH.

[Simpo Two]

Thanks, one more fact under the bonnet.

Wow, a^6 is a lot of a's!