Posted by Adriana on Wednesday, October 28, 2009 at 4:39pm.
I had to solve the function g of f where f is x^2+1 and g is sq. root of x. I wrote this out as the sq. root of x^2+1. The ^2 and the sq. root canceled each other out, so I was left with x + sq. root of 1. But my book got sq. root of x^2+1. Was the further reducing I did acceptable or inaccurate?

Algebra  jim, Wednesday, October 28, 2009 at 6:21pm
You can't separate the added parts and take the square root of each. (You could if they were multiplied, but not if added.)
I will show a counterexample.
You were looking at sqrt(x^2+1).
Consider this example  let x=3, then we have :
sqrt(3^2+1) = sqrt(9+1) = sqrt(10)
Now, you would have said that this was equal to
3 + sqrt(1) = 4.
But 4 is not the square root of 10.
We can get in deeper about why your approach doesn't work if you like, but this counterexample is enough to show it's not true.

Algebra  Adriana, Wednesday, October 28, 2009 at 10:47pm
Thank you :D That really cleared it up! I never had anyone explain that concept so well before.
Answer This Question
Related Questions
 Algebra  I had to solve 2x^2x1 using the quad. formula. I got it down to (1...
 Algebra  Rationalize each expression by building perfect nth root factors for ...
 maths surds please help and explain  Simplify A.1/root a +2 b.root 18/25 c.root...
 Math simplifying mixed radicals  Please help me simplify these following mixed ...
 Math simplifying mixed radicals  Please help me simplify these following mixed ...
 Algebra  Use the quadratic formula to solve the equation. Give exact answers: ...
 Roots and Precal  Find the roots of the function f(x)= x^2 +2x+2 a)1 + sq ...
 algebra 2  Not sure if either one of these answer are correct to simplify the ...
 Algebra 2  could you walk me thorugh these problems simplfy square root 18  3 ...
 Math  What is the square root of 12? 3.464 Well, that's true, but you could ...
More Related Questions