Question

g(x)=(2+x)(7+x)(8+x)

find g'(x)

Answer 1

how would i do a problem like this

Answer 2

saiberz, u there?

Answer 3

(f(x)*g(x))' = f'(x)*g(x) + f(x)*g'(x)
so you can do it twice:
g(x) = (2+x)'*(7+x)(8+x) + (2+x)*[(7+x)(8+x)]'
g(x) = (1)(7+x)(8+x) + (2+x) [(7+x)'(8+x)+(7+x)(8+x)']
g(x) = (7+x)(8+x) + (2+x)*[(1)(8+x)+(7+x)(1)]
i hope it helps you

Answer 4

o so i gotta use the product which i havent mastered yet lol

Answer 5

i meant to say product rule lol

Answer 6

so what would be the final answer?

Answer 7

just operate it
g(x) = (7+x)(8+x) + (2+x)*[(1)(8+x)+(7+x)(1)]
g(x) = x^2+15x+ 56 + 2x^2 + 19x +30
g(x) = 3x^2 + 34x +86
check it
i'm not sure

Answer 8

o

Answer 9

2x^2 + 19x +30

howd u get that ^^^

Answer 10

(2+x)*[(1)(8+x)+(7+x)(1)] is not that?

Answer 11

can u show me the steps please. sorry if im being complicated. i know how to FOIL but i always forget what to do when theres 3 rather 2 sets to FOIL out.

Answer 12

u left :(

Answer 13

just multiply :
(2+x)*(8+x + 7 + x)
(2+x)*(15+2x)
30 + 15x + 4x +2x^2
2x^2 + 19x + 30

Answer 14

i add? ...o i see

Answer 15

Yes, it is correct. Thanks for all the help. It is appreciated.

Answer 16

you are welcome