- #1
studentxlol
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Homework Statement
Show that the gradient of the curve [tex]\frac{a}{x}+\frac{b}{y}=1[/tex] is [tex]-\frac{ay^2}{bx^2}[/tex]. The point (p,q) lies on both the straight line [itex]ax+by=1[/tex] and [tex]\frac{a}{x}+\frac{b}{y}=1[/tex] where ab =/= 0. Given that, at this point, the line and the curve have the same gradient, show that p=±q.
The Attempt at a Solution
[tex]\frac{a}{x}+\frac{b}{y}=1[/tex]
[tex]\frac{dy}{dx}=-ax^{-2}-by^{-2}[/tex]
[tex]-\frac{b}{y^2}\frac{dy}{dx}=\frac{a}{x^2}[/tex]
[tex]\frac{dy}{dx}=-\frac{ay^2}{bx^2}[/tex]
Homework Statement
Not sure how to calculate the next part..