HELPP find the tangents of the curve x^2+ y^2 - 6x + 4y = 0 from (-17, 7). the answers are 2x+3y+13=0 and 34x+129y = 325..

Question

anonymous · Answer

http://www.weegy.com/

anonymous · Answer

ha?

anonymous · Answer

@phi :) this is the last.. very last

phi · Answer

Here is a picture

anonymous · Answer

okay

anonymous · Answer

i messed up again in the cross multipying part.. o men

phi · Answer

these are wicked.
I got 
$$ \frac{dy}{dx}= \frac{-(x-3)}{(y+2)}$$
and the slope equation
$$ \frac{-(x-3)}{(y+2)}= \frac{(y-7)}{(x+17)}$$
or,after cross multiplying:
$$ -(x-3)(x+17)= (y+2)(y-7) $$

phi · Answer

I see I lost a sign.  
we work the cross multiply equation into the form
$$ x^2+y^2= -14x+5y+65 $$
now use the original equation
$$ x^2 +y^2= 6x-4y $$

$$ 6x-4y = -14x+5y+65 $$
solve for y to get
$$ y = \frac{20x-65}{9} $$

phi · Answer

now replace y with that expression in the cross multiply equation As this is very tedious, I used Wolfram to do the hard work. http://www.wolframalpha.com/input/?i=-%28x-3%29%28x%2B17%29%3D+%28y%2B2%29%28y-7%29%2C+y+%3D+%5Cfrac%7B20x-65%7D%7B9%7D