## anonymous one year ago given f(x)=4x^2-3 and g(x)=-3x^2+4,find (f.g)(x) AWAAAAARDDDD!!!1

1. anonymous

$f\circ g$ or $f\times g$?

2. anonymous

F x g @satellite73

3. anonymous

put a times sign between them use parentheses

4. anonymous

what do you mean like (fxg)?? @satellite73

5. anonymous

can u demonstrate because i have 7 problems like this and i want to get a good grade @satellite73

6. SolomonZelman

what is  (4x²-3) × (-3x²+4)  ?

7. SolomonZelman

the first part, the 4x²-3 is f, and the second part, the -3x²+4 , is the g. that is what they mean by f × g

8. SolomonZelman

all I am trying to say that in the following case, $$\large\color{black}{ \displaystyle f(x)=4x^2-3 ~~~~{\rm and}~~~~ g(x)=-3x^2+42}$$ the (f×g)(x) is going to be $$\large\color{black}{ \displaystyle (f×g)(x)=\left(4x^2-3\right)\times \left(-3x^2+42\right)}$$

9. SolomonZelman

so you are to multiply what f(x) is equal to, BY what g(x) is equal to.

10. SolomonZelman

is this making some sense?

11. anonymous

yes it is ! so do i basically simplify it? @SolomonZelman

12. SolomonZelman

yes.

13. SolomonZelman

when you expand that product, tell me what you get:)

14. anonymous

would it be something like 4x^2+2x-3? pr 6x^2-3 or just 4x^3-2 ?????? @SolomonZelman

15. SolomonZelman

you are multiplying....

16. SolomonZelman

(4x²−3) × (−3x²+42)

17. anonymous

idk this topic sir , its really confusing @SolomonZelman

18. anonymous

for this question : |dw:1435632928544:dw|

19. anonymous

@SolomonZelman ^^^^

20. SolomonZelman

8x³-12x² it would be for the problem you posted just now

21. SolomonZelman

i suggest to go back and review multiplication of variables with different coefficients and powers, factoring and all that.