Question

How to Define the following functions?

help please..

1. f(x)=x-5; g(x)= x^2-1

a. f+g

b. f-g

c. f⋅g

d. f/g

e. g/f

Answer 1

a. f+g
(x-5)+(x^2-1) = x^2+x-6

b. f-g
(x-5)-(x^2-1) = -x^2+x-4

Answer 2

@mathslover help here please..

Answer 3

You have got the first two right. Just continue on. Multiply the two functions for c. Divide f by g for d and take its reciprocal for e

Answer 4

@ranga how to solve for multiplication and division ??

Answer 5

f.g = (x-5)(x^2 - 1)
Expand the above.

Answer 6

can you show me how to expand it??

Answer 7

how if we use the FOIL method in the multiplication ??

Answer 8

Use FOIL.

Answer 9

(a+b)(c+d) = ac + ad + bc + bd

Answer 10

(x-5)(x^2 - 1) = x^3 -x -5x^2 + 5 = x^3 - 5x^2 - x + 5

Answer 11

f/g = (x - 5)/(x^2 - 1)

Answer 12

okok

Answer 13

i dont know the proess if it is in division..

Answer 14

@ranga still there ??

Answer 15

f/g = (x - 5)/(x^2 - 1)
is the answer for f/g.
If you wish you can factor the denominator:
f/g = (x - 5)/{(x + 1)(x - 1)

But either one should be ok.

For the last one (e) just take the reciprocal of (d)

Answer 16

can you show me the solution of (e)??

Answer 17

g/f = (x^2 - 1) / (x - 5)
That is all.

Answer 18

so the final answer for (d) is f/g = (x - 5)/{(x + 1)(x - 1)}

Answer 19

Yes. Either form is acceptable:
f/g = (x - 5) / (x^2 - 1) or f/g = (x - 5) / { (x + 1)(x - 1) }

Answer 20

ok , for (e) can you show me the solution??

Answer 21

g/f=(x^2 - 1) / (x-5) ???

Answer 22

Yes. That is it.

Answer 23

g/f={(x+1)(x-1)} / (x-5)

Answer 24

That is acceptable too. Either form is okay.

Answer 25

thank you Ranga =)