clearmountain wrote:

Hi.

i had an inscribed angle problem asking for the lenght of one of the sides.

the answer was 4 +2rad2.

the answer key says I am supposed to get this by factoring this quadratic y^2 + 8Y + 8 = 0.

how do i do that?

thanks,

Clearmountain

If the answer is

4+2\sqrt{2} then the equation must be

y^2-8y+8=0.

You can use the formula which gives the roots of a quadratic equation in terms of its coefficient.

Another way is as follows:

y^2-8y+8=y^2-8y+16-8=(y-4)^2-8=0 from which

(y-4)^2=8 and either

y-4=2\sqrt{2}, so

y=4+2\sqrt{2},

or

y-4=-2\sqrt{2}, which gives

y = 4-2\sqrt{2}.

_________________

PhD in Applied Mathematics

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