Question

The curve y=X^2+A÷X has the gradient of 7 when X=4.calculate the value of A

Answer 1

$\frac{dy}{dx}=2x-\frac{A}{x^2}$

When x=4: $\frac{dy}{dx}=8-\frac{A}{16}$

So, $8-\frac{A}{16}=7$

and $A=16.$