Thursday

April 17, 2014

April 17, 2014

Posted by **CheezyReezy** on Friday, June 3, 2011 at 1:46am.

f(x) = √x; g(x) = 2x + 12

- Math - Domain of Composite function -
**Jai**, Friday, June 3, 2011 at 6:06amf(x) = sqrt(x)

g(x) = 2x + 12

thus,

(fog)(x) = sqrt(2x + 12)

note that to get the domain, you must get the intersection of the 3 function domains.

for f(x) = sqrt(x), x cannot be less than zero thus the domain is [0 , +infinity)

for g(x) = 2x + 12, x can be any real number thus domain is (-infinity, +infinity).

for (fog)(x) = sqrt(2x + 12), the lowest possible value of the radicand (term inside the radical sign) is zero. thus equating 2x + 12 to zero,

2x + 12 = 0

x = -6

thus domain is [-6 , +infinity)

the intersection of the three domains is therefore,

[0, +infinity)

hope this helps~ :)

**Related Questions**

Math - Domain of Composite - Find the domain of the composite function . Please ...

Domain of composite function - Can you please help me with the following ...

Domain of composite function - Find the domain of the composite function fog. f(...

math - Find the domain of the composite function f of g. f(x)=3/x-6; g(x)= 1/x ...

math - find the domain of composite function fog f(x)=x/x-4; g(x)= -1/x please ...

college algebra--need help please!! - find the domain of the composite function ...

alg - find the domain of the composite function f of g. f(x)=x^2+9;g(x)=sqrtx-7...

college algebra--I really need help!! - Find the domain of the composite ...

math - find the domain of the composite function fog. f(x)=x/x-2;g(x)=-8/x a. ...

college algebra - Let f(x) = square root (x + 2) and g(x) = x^2 − 2. ...