Hi

I have some question i am having trouble with:

1)If the angle between the lines which passes through the points (-2,3) and (4,0) is:

A$\displaystyle 2y=x+4$

B$\displaystyle y=\frac{-x}{2}-2$

C$\displaystyle 2y+x=4$

D$\displaystyle y=\frac{x}{2}-2$

E$\displaystyle 2y-x=4$

2)Find the derivative of $\displaystyle (4x+\frac{9}{x})^2$ and values of x at which the derivative is zero

3)Let f be differentiable for all values of x in [2,0]. The graph with equation y=f(x) has a maximum point at (1,3). The equation of the tangent at (1,3) is:

A$\displaystyle x+3y=0$

B$\displaystyle x=1$

C$\displaystyle y=3$

D$\displaystyle x-3y=0$

E$\displaystyle 3x+y=0$

P.S