Question 969396: if p(x)=x²-2√2x+1 then find the value of p(2√2)
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! Substitute 2sqrt(2)
[2 sqrt (2)]^2 - [2(sqrt (2)} * [2 sqrt (2)] +1
Notice the second term in the sum is {2 (sqrt(2)]^2, the same as the first term, but opposite sign.
They cancel, and you are left with 1 as the answer.
NOTE: I am assuming that the second term in the sum is [2 (sqrt(2)] *x and NOT [2 sqrt (2x)]. In other words, the radical is only over the 2 and not over both the 2 and the x. That would change the answer.
In the solution I gave, you can square 2 *sqrt (2) . You get 4*2=8. But if you can see that the second term is the same as the first, and is opposite sign, those two terms cancel, and you don't have to deal with squaring radicals. If x were under the radical, then there would be a 4th root of 2 in the answer, which I doubt is what the question is about. I just bring it up, because what is under the radical and what isn't is critical.
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