If #f(x)=sqrt(x+3)# and #g(x)=8x-7#, what is #f(g(x))#?

1 Answer
Nov 8, 2016

#f(g(x))=2sqrt(2x-1)#

Explanation:

To evaluate f(g(x)), substitute the value of g(x) for x in f(x).

#rArrf(g(x))=f(color(red)(8x-7))=sqrt(color(red)(8x-7)+3)=sqrt(8x-4#

#color(orange)"Reminder " color(red)(bar(ul(|color(white)(2/2)color(black)(sqrtaxxsqrtbhArrsqrt(ab))color(white)(2/2)|)))#

#rArrsqrt(8x-4)=sqrt(4(2x-1))=sqrt4xxsqrt(2x-1)#

#=2sqrt(2x-1)#