SOLUTION: given f(x)=x^2-4, g(x)=sqrt of x+1 find and simplify f[g(1/2)] Im lost!!! please help!

Algebra ->  Functions -> SOLUTION: given f(x)=x^2-4, g(x)=sqrt of x+1 find and simplify f[g(1/2)] Im lost!!! please help!      Log On


   

Question 265062: given f(x)=x^2-4, g(x)=sqrt of x+1
find and simplify f[g(1/2)]
Im lost!!! please help!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29=x%5E2-4 Start with the first function


f%28g%28x%29%29=%28sqrt%28x%2B1%29%29%5E2-4 Plug in g%28x%29=sqrt%28x%2B1%29


f%28g%281%2F2%29%29=%28sqrt%281%2F2%2B1%29%29%5E2-4 Plug in x=1%2F2


f%28g%281%2F2%29%29=%28sqrt%283%2F2%29%29%5E2-4 Add the fractions.


f%28g%281%2F2%29%29=3%2F2-4 Take the square root of sqrt%283%2F2%29 to get 3%2F2


f%28g%281%2F2%29%29=-5%2F2 Subtract.


So the solution is f%28g%281%2F2%29%29=-5%2F2