Differentiation A’s help plz

sunflower69

9

22c) how?
And 24) how do I work out what the gradient function is

Reply 1

The Pensive One

4

Hi, Have you uploaded a picture of your questions or a screenshot?

Reply 2

sunflower69

OP

9

Original post by The Pensive One

Hi, Have you uploaded a picture of your questions or a screenshot?

Ya forgot to do that silly me

Reply 3

mqb2766

21

22c) You want to find the minimum of OP^2. This is a disguised quadratic, so just find the minimum value of it Most of the work has been done in a) and b).

24) Sketch the gradient. Where is the gradient zero (tangent is flat). Where is the gradient postive (functions goes upwards)? Where is the gradient negative (function goes down)? Where are the largest postive and negative gradients (where does the function change rapidly).

Reply 4

The Pensive One

4

Hey (its a bit late sorry)
for 22c) i would find the second derivative of the given f(x), and then equal to zero, find the values of x which satisfy this equation. Then substitute back into f(x) to find the corresponding values of f(x), you then substitute the values of 'x' back into the second derivative, if the second derivative is greater than zero, then you have a minimum point. Together with the value of f(x) you have a minima (minimum point)
(i think finding the distance between this minima and the origin would then give you the minimum distance).

for 24 https://www.youtube.com/watch?v=Kz_reJgi_Rg (i think this is an excellent video :wink:

)

(let me know if seeing a calculation is easier)

Reply 5

sunflower69

OP

9

Original post by mqb2766

22c) You want to find the minimum of OP^2. This is a disguised quadratic, so just find the minimum value of it Most of the work has been done in a) and b).

24) Sketch the gradient. Where is the gradient zero (tangent is flat). Where is the gradient postive (functions goes upwards)? Where is the gradient negative (function goes down)? Where are the largest postive and negative gradients (where does the function change rapidly).