document.write( "Question 1065873: Determine the point \"P%28x%2C+y%29+\" on the graph of the equation \"y=+sqrt+%28x%2B1%29+\" such that the slope of the line through the point (3, 2) and P is 3/8 \n" ); document.write( "
Algebra.Com's Answer #681053 by Boreal(15235)\"\" \"About 
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\"graph%28300%2C300%2C-10%2C10%2C-10%2C10%2Csqrt%28x%2B1%29%29\"
\n" ); document.write( "The point is (x,y). The slope is (2-y)/(3-x)=(3/8)
\n" ); document.write( "That is 16-8y=9-3x
\n" ); document.write( "or 3x+7=8y; but y = sqrt (x+1)
\n" ); document.write( "right side is 8 sqrt (x+1)
\n" ); document.write( "square both sides
\n" ); document.write( "9x^2+42x+49=64(x+1)=64x+64
\n" ); document.write( "9x^2-22x-15=0
\n" ); document.write( "(9x+5)(x-3)=0
\n" ); document.write( "x=3 (doesn't help) and x=-5/9
\n" ); document.write( "y is sqrt ( -5/9 +1)= sqrt (4/9) =2/3
\n" ); document.write( "the slope between (-5/9,2/3) and (3,2)=2-(2/3) or 12/9 divided by 3-(-5/9)=32/9
\n" ); document.write( "12/9 divided by 32/9 is 3/8.
\n" ); document.write( "The point has to be to the left of (3,2), because the derivative is 1/2 sqrt (x+1), which at x=3 gives a slope of 1/(2*2)=1/4, and the slope gets less further to the right.
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