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Factor the expression over the complex numbers.

 

y^2+49

 Sep 12, 2018
 #1
avatar+2442 
0

I believe this is how you do it.

Use the formula to factor: a^2+b^2=(a+b)(a-b)

y^2 is already a perfect square.

49=7*7=7^2 and that's your other perfect square.

Now your expression is y^2+7^2=(y-7)(y+7)

 Sep 12, 2018
 #2
avatar+2442 
0

Either that or you can't factor it at all

RainbowPanda  Sep 12, 2018
 #3
avatar+27529 
+1

That's not quite right RP!  The general expression is a2 - b2 = (a + b)(a - b)

 

Here we have a = y, but b = 7i, where i is the square root of -1.

 

So y2 + 49 → y2 - (7i)2 → (y + 7i)(y - 7i)     (Note that i2 = -1)

Alan  Sep 12, 2018
 #4
avatar+2442 
0

Figures, I knew the actual equation but I thought that was only for - and not +. Thanks for correcting me though!

RainbowPanda  Sep 12, 2018

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