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anonymous
 4 years ago
Ok, I need help figuring out, (7 + sqrt5) ^2. I know it's rewritten as (7 + sqrt 5) (7 + sqrt 5).
Do I use FOIL to figure this out?
anonymous
 4 years ago
Ok, I need help figuring out, (7 + sqrt5) ^2. I know it's rewritten as (7 + sqrt 5) (7 + sqrt 5). Do I use FOIL to figure this out?

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KingGeorge
 4 years ago
Best ResponseYou've already chosen the best response.1FOIL would be an excellent strategy in this case.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0Yes, but rewrite it. sqrt 5 means imaginary..

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0dw:1327303757412:dw

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0how do I rewrite it? I think that's the part that's stumping me

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0oh wait, Cinar already did. Thanks! so sqrt 5 equals sq root 5i?

KingGeorge
 4 years ago
Best ResponseYou've already chosen the best response.1The equation you have is the following correct?\[(7 + \sqrt{5})^2\]

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0dw:1327303914040:dw

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0@kinggeorge: Yes, that is correct! how did you get the square root symbo??

KingGeorge
 4 years ago
Best ResponseYou've already chosen the best response.1If you go into the equation editor on the bottom left of the comment box. For example, you can type "sqrt{5}" without the quotes to get \[\sqrt{5}\]It takes some getting used to, but is very clear. Moving on, since that is the equation, cinar's solution is correct.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0I know it's the imaginary units that are throwing me off

KingGeorge
 4 years ago
Best ResponseYou've already chosen the best response.1As for imaginary units, the square root of negative one is defined as the letter i. Or, \[\begin{matrix} \sqrt{1} = i \\ i^2 = 1 \end{matrix}\]So if you have a radical such as \[\sqrt{20}\] you can simplify and solve like so\[\sqrt{20} = \sqrt{(1) \cdot 4 \cdot 5} = \sqrt{1} \cdot \sqrt{4} \cdot \sqrt{5} = 2i \sqrt{5}\]

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0wow, this is great!! thank you so much. It's making a lot more sense to me now!
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