f(x)=2sqrt(x-1) and g(x)=sqrt(x-1)
Find and state domain
f(x)*g(x)

Question

f(x)=2sqrt(x-1) and g(x)=sqrt(x-1)
Find and state domain
f(x)*g(x)

shayaan_mustafa · Answer

i have answer i.e. 2x-2
but what about domain?

apoorvk · Answer

domain is what values x may take in a function for being defined. here x can take any real value for being defined no constraints so domain is all real nos.

shayaan_mustafa · Answer

yes i write as you said. but the answer is wrong. not all x's

amistre64 · Answer

sqrt(n); n>=0

shayaan_mustafa · Answer

ok amistre64 how can you say? but look at answer. there is not any sqrt in answer. simple 2x-2

amistre64 · Answer

the domain of the function dont change since they are in integral part of the problem so we have to "and" theyre respective domains together

shayaan_mustafa · Answer

it is a questio from howard anton calculus. and according to book domain should be x>=1

apoorvk · Answer

but in f(x), |dw:1332517010644:dw|

because anything under a sq root can not be negative. so x has to be greater than one which is the domain of f(x). similar in g(x).

oh yes.. hmm in f*g, although the final function is 2x-2 but the original factors are in roots right? so x will have to be greater than 1 there as well. but if someone asks you simply whats domain 2x-2 then we can say all real.