The curve with equation y=f(x),x>0y = \mathrm{f}(x), x > 0y=f(x),x>0, passes through the point P(9,−5)P(9, -5)P(9,−5).
Given that
dydx=2xx−12x−12 \frac{\mathrm{d} y}{\mathrm{d} x} = 2x\sqrt{x} - 12x^{-\frac{1}{2}} dxdy=2xx−12x−21Find the equation of the tangent to the curve at PPP, writing your answer in the form y=mx+cy = mx + cy=mx+c, where mmm and ccc are integers to be found.
Find f(x)f(x)f(x).