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nlexa [21]
3 years ago
8

Quadratic formula 2x²+9x-4=0

Mathematics
2 answers:
posledela3 years ago
5 0
2x^2+9x-4=0\ \ \ \ /:2\\\\x^2+\frac{9}{2}x-2=0\\\\x^2+2x\cdot\frac{9}{4}+(\frac{9}{4})^2-(\frac{9}{4})^2=2\\\\(x+\frac{9}{4})^2-\frac{81}{16}=2\\\\(x+\frac{9}{4})^2=\frac{32}{16}+\frac{81}{16}\\\\(x+\frac{9}{4})^2=\frac{113}{16}\iff x+\frac{9}{4}=-\sqrt\frac{113}{16}\ \vee\ x+\frac{9}{4}=\sqrt\frac{113}{16}\\\\x=-\frac{9}{4}-\frac{\sqrt{113}}{4}\ \vee\ x=-\frac{9}{4}+\frac{\sqrt{113}}{4}\\\\x=-\frac{9+\sqrt{113}}{4}\ \vee\ x=-\frac{9-\sqrt{113}}{4}
blondinia [14]3 years ago
4 0
2x^2+9x-4=0 \\ \\a=2 , b =9 , \ c=- 4 \\ \\\Delta = b^{2}-4ac = 9^{2}-4*2* (- 4)= 81+32 =113 \\ \\x_{1}=\frac{-b-\sqrt{\Delta }}{2a} =\frac{-9- \sqrt{113}}{4} \\\\x_{2}=\frac{-b+\sqrt{\Delta }}{2a} = \frac{-9+\sqrt{113}}{4}


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Now plug these numbers into the rise over run formula:

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<span><span><span>1. An altitude of a triangle is a line segment from a vertex perpendicular to the opposite side. Find the equations of the altitudes of the triangle with vertices (4, 5),(-4, 1) and (2, -5). Do this by solving a system of two of two of the altitude equations and showing that the intersection point also belongs to the third line. </span>
(Scroll Down for Answer!)</span><span>Answer by </span>jim_thompson5910(34047)   (Show Source):You can put this solution on YOUR website!
<span>If we plot the points and connect them, we get this triangle: 

 

Let point 
A=(xA,yA)
B=(xB,yB)
C=(xC,yC) 



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Simplify and combine like terms 

 


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Plug in the given points 

 


Simplify and combine like terms 

 


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Simplify and combine like terms 

 


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------------------------------------------------------------ 
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So the orthocenter lies on the third altitude 





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