help in questions please...

[FromBaghdadWithLove]

hey can u guys help me out a little..

i cant solve these

and these...

[azure]

6) Use product rule, let f'(x) = 0, solve for x. Sub x back into original equation to find y.

7) Y-axis => when x= 0, find y coordinate.
Differentiate equation y= x^2 + x - 12.
Find dy/dx|2.
Normal = perpendicular... hence find the gradient of the normal (-1/m)
Sub coordinates that you found in the first step into equation y=mx + c (assuming you have found the gradient already) to find c.
There you go, you have the normal. Just rearrange to find the answer.

Basically the same as above except you're not finding the normal but the tangent so skip step 4.

9) Same as question 8

10) Hint: find gradient of the second equation.

11) Same as question 10.

[HenryP]

For the first question you want to find the derivative so you can find the stationary point.
So

Let the derivative equal to 0 to find stationary points


Sub back into the original equation you get the co-ordinates (-1,e)