Question

when simplifying [3(x/3)+5]-15 i get x-10, is there any values of x that i should exclude from the composite function such that x cannot equal ?

Answer 1

i'm sorry, i just get x

Answer 2

no it's x-10. u musnt multiple 5 by 3. x-10 is ok.

Answer 3

when i put it into wolframalpha it said x /: ahhhhh

Answer 4

maybe u write it wrong in wolframalpha

Answer 5

yes, i've copied and pasted and got x-10

Answer 6

oh, ok. thank you. now, for the second part of the question, im given [(3x-15)/(3)]+5. i also got x for this one. would these be composite functions...if the first one is x-10 and the second one is x?

Answer 7

and i did type it wrong into wolfrmalpha. it is supposed to be x for the first one. the 3 should be outside of the parentheses

Answer 8

i think u mean f(x)=x-10 and g(x)=x then u ask (fog)(x), answer is x-10. i think u can do it.

Answer 9

noo. the composites are f(x)=3x-15 and g(x)=(x/3)+5

Answer 10

i just dont want to write answer, look at http://www.mathsisfun.com/sets/functions-composition.html then if u still cant come over it let me know

Answer 11

so x for them isnt right when f0g and gof?

Answer 12

there is not number that you need to exclude because f(x) and g(x) are linear functions

Answer 13

and they both simplify to x, right?

Answer 14

are they inverses of each other?

Answer 15

not all compositions will simplify to x

Answer 16

yeah x is right