f(x) = x2 - 16 and g(x) = x+4. Find f/g and its domain.
A. x - 4; all real numbers except x \[\neq-4\] B. x + 4; all real numbers except x \[\neq-4\] C. x + 4; all real numbers except x \[\neq4\] D. x - 4; all real numbers except x\[\neq4\]
I am not good at math :\
I'm soooo sorry but I'm not good at math either. :s @suckerofmath can you help? c:
I have no idea sorry.
She is intelligent in an inarticulate manner ^.^ Just kidding Tea :p
Lol ohh wow
So first we know that a^2 - b^2 = (a -b) * (a + b) ==> x^2 - 16 = x^2 - 4^2 = (x+4) * (x - 4) Since we are finding domain of f/g = (x+4)*(x - 4)/(x+4) = (x - 4) So Domain of (x - 4) is ??? this function f/g is exist for all real values therefore Domain is R
I have no idea here
Okay We are finding domain of f/g = x^2 - 16 /x+4 right ?
yes
& we know that a^2 - b^2 = (a -b) * (a + b) So we can write x^2-16 as =x^2 - 4^2 = (x- 4) * (x + 4) okay ?
ok
So we have got f/g = (x + 4) * (x - 4) / (x +4) right ?
yup
Now we cancel common factor fro numerator & denominator So we will get f/g = (x + 4)*(x-4)/(x+4) = (x - 4) Ok ?
ok
Answer is D ?
Now we have f/g = (x - 4) & we are finding domain Domain is the set of values for which function is defined or function make sence So Here at any value of x our function f/g is defined , that is if we put any real number instead of x we get some answer that is function is defined at all real values Hence Domain = R
Is D the answer ?
no please check it the function is undefined when denominator is zero our original function f / g = x^2 - 16 / (x + 4) so at what value denominator become zero ?
A ?
thanks
u r welcome :)
#Shay17 #tgawade was the answer to this problem A? I'm so lost right now
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