MHB *2 values of x for perpendicular vectors

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The discussion centers on finding the values of x for which the vectors (2x/(x-3)) and ((x+1)/5) are perpendicular. The quadratic equation derived is 2x^2 + 7x - 15, yielding potential solutions of x = -5 and x = 3/2. Initially, there was confusion regarding the validity of x = 3/2, as it seemed not to produce perpendicular slopes. However, upon further examination, the error was identified, confirming that both values are indeed correct. The conversation highlights the importance of careful calculation in vector analysis.
karush
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The vectors $$\left(\frac{2x}{x-3}\right)$$ and $$\left(\frac{x+1}{5}\right)$$ are $$\perp$$ for $$2$$ values of $$x $$

what is the quadratic equation which the 2 values of x satisfy

well I got $$2x^2+7x-15$$ which gives $$x=-5$$ and $$x=\frac{3}{2}$$
-5 seems to work but
$$\frac{3}{2}$$ doesn't or is there another way to do this.

thanks ahead,
 
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Re: 2 values of x for perpendicular vectors

karush said:
The vectors $$\left(\frac{2x}{x-3}\right)$$ and $$\left(\frac{x+1}{5}\right)$$ are $$\perp$$ for $$2$$ values of $$x $$

what is the quadratic equation which the 2 values of x satisfy

well I got $$2x^2+7x-15$$ which gives $$x=-5$$ and $$x=\frac{3}{2}$$
-5 seems to work but
$$\frac{3}{2}$$ doesn't or is there another way to do this.

thanks ahead,

Hi karush! :)

What is the reason you think $x=\frac 3 2$ does not work?
It is a proper solution.
 
Re: 2 values of x for perpendicular vectors

when I plugged $$\frac{3}{2}$$ in the slopes didn't seem $$\perp$$
 
Re: 2 values of x for perpendicular vectors

karush said:
when I plugged $$\frac{3}{2}$$ in the slopes didn't seem $$\perp$$

Well... which vectors do you get if you plug it in?
 
Re: 2 values of x for perpendicular vectors

OK found my error...
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

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