Question

How to work out, Integral of (3-x)((7^(3-x)^2)) dx?

Answer 1

\[\Huge \int\limits(3-x)7^{\color{#CC0033}{(3-x)^2}}\;dx\]
Let u= this red part.

Answer 2

\[\Large du=?\]:D

Answer 3

\[\frac{ -7^{(3-x)^{3}} }{ 3\ln(7) }\]

Answer 4

Don't simply post answers.
Help the person through the problem -_-

Answer 5

is du, (3-x)^2 and do you bring the 2 down and make if 2(3-x)?

Answer 6

the suspense was killing me >.<

Answer 7

yes with dx at the end

Answer 8

Would u distribute the 2 in?

Answer 9

and a - in front

Answer 10

no

Answer 11

so would dx be du/-2?

Answer 12

du = -2(3-x)dx

Answer 13

yes

Answer 14

remember with u sub you try to substitute all x out

Answer 15

why do you need a - in the front?

Answer 16

chain rule

Answer 17

you also take a derivative of the inside and multiply

Answer 18

derivative of 3 = 0 + derivative of -x = -1

Answer 19

go to this website watch some videos under chain rule great explanations. http://patrickjmt.com/

Answer 20

thank you

Answer 21

no problem, that website is a lifesaver for math