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Calculus: I keep getting this question wrong can you help?
Ok here is the question:
Find the equation of the tangent line to the graph of -2x/(x^2+1) at the Origin and at the point (1,-1)
I got 4 of these right in a row but keep getting wrong answers for this one. please show the steps used along with the answer so I know where I went wrong
1 Answer
- TomVLv 71 decade agoFavorite Answer
y = -2x/(x²+1)
y' = [-2(x²+1) + 2x(2x)]/(x²+1)² = (4x²-2x²-2)/(x²+1)² = 2(x²-1)/(x²+1)²
y'(0) = -2
y'(1) = 0
The tangent line at the origin has slope -2 and passes through point (x,y) = (0,0):
y = -2x
The tangent line at the point (1,-1) has slope 0 (horizontal) and passes through the point (x,y) = (1,-1):
y = -1
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