Question 1099730
{{{2xdx+2ydy=0}}}
{{{ydy=-xdx}}}
{{{dy/dx=-x/y}}}
The slope of the tangent line is equal to the value of the derivative at the tangent point,
{{{m=-x/y=-3/4}}}
So using point-slope form,
{{{y-4=-(3/4)(x-3)}}}
{{{4y-16=-3(x-3)}}}
{{{4y-16=-3x+9}}}
{{{highlight(3x+4y=25)}}}
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*[illustration CRC4.JPG].