Friday, November 27, 2015

Does the curve 2x^2=10 have x intercepts?

The two answers above show how to find the x-intercepts
through factoring.  You could also find them using the quadratic formula and by
graphing.


Method 1.  Quadratic
Formula


2x^2=10


2x^2 - 10 =
0


2x^2 + 0x + -10 = 0


a = 2, b
= 0, c = -10


x = [-b class="AM">`+-` sqrt(b^2 - 4ac)] / 2a


x =
[-0 `+-` sqrt(0^2 - 4*2*-10)] /
2*2


x =`+-` sqrt(80) /
4


x = `+-` 4sqrt(5) /
4


x = class="AM">`+-`
sqrt(5)



Method 2: 
Graphing


2x^2=10


2x^2 - 10 =
0


Graph y = 2x^2 -
10


src="/jax/includes/tinymce/jscripts/tiny_mce/plugins/asciisvg/js/d.svg"
sscr="-4,4,-10,2,1,1,1,1,1,300,200,func,2x^2-10,null,0,0,,,black,1,none"/>


The
x-intercepts are `+-`
sqrt(5).

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