Friday

July 25, 2014

July 25, 2014

Posted by **Saud** on Wednesday, November 21, 2012 at 11:44am.

Two functions f and g are defined by

f:x(arrow)x^2 + 3

g:x(arrow)2x + 1

find:

a) the function fg

b)solve the equation f(x) = 12g^-1(x)

Many Thanks!!!!

- Maths -
**Steve**, Wednesday, November 21, 2012 at 12:37pmusing the usual notation,

f(x) = x^2+3

g(x) = 2x+1

fg = f(x)*g(x) = (x^2+3)(2x+1) = 2x^3 + x^2 + 6x + 3

f(x) = 12g^-1(x)

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

so, solve x^2+3 = 12(x-1)/2

x^2+3 = 6x-6

x^2 - 6x + 9 = 0

(x-3)^2 = 0

x = 3

- Maths -
**Steve**, Wednesday, November 21, 2012 at 12:39pmIf by fg you meant f◦g (that is, f(g(x))), then

since f(x) = x^2+3,

f(g) = g^2+3 = (2x+1)^2+3 = 4x^2 + 4x + 4

**Related Questions**

MATHS - Critical help please. Level 3 maths algebraic methods is really hard. Q...

physics - You are watching an archery tournament when you start wondering how ...

Complex Algaebra, Plz Help!! - Good evening to all around the world. Need help ...

coefficient - test using the lead coefficient to find out if y arrow oo, or y ...

Physics - Three arrows are shot at different angles. A red arrow is shot at ...

physics - An arrow is short vertically upward with an initial speed of 25m/s. ...

Physics - Problem: A hunter shoots an arrow at a deer directly away from him. ...

physics - You are watching an archery tournament when you start wondering how ...

physics - You are watching an archery tournament when you start wondering how ...

physics - You are watching an archery tournament when you start wondering how ...