# Answer to Question #4134 in Abstract Algebra for robin

Question #4134

I have to use mathcad to solve this question

A ď¬‚exible wire P QRS, of total length 12 metres, is bent into a three-edged

planar shape, and its ends P, S are placed against a disc of

radius 9 metres with centre O, as shown in the diagram below. (The arc

P S is not part of the wire.) The end-segments P Q and RS of the wire lie

along straight lines through O, while the arc QR forms part of a circle

with centre O and subtends an angle x (in radians) at O.

This question concerns the area A enclosed between the wire and the edge

of the disc, which is shown shaded below. This area can be expressed by

A = f(x), where

f(x)=9x(4 − 3x)(16 + 3x) / 2(2+x)^2

0 ≤ x ≤4/3

(a) (i) Plot the graph of the function f(x). Your graph should cover the

interval [0, 1.33] in the x-direction and [0, 20] in the y-direction.

(ii) By using the ‘Trace’ facility (and also, if you wish, the ‘Zoom’

facility), estimate to two decimal places the coordinates of the

point on this graph at which y = f(x) takes its maximum value.

(iii) On the same graph, plot the line y = 8. Using the ‘Trace’ facility,

estimate to two decimal places both solutions of the equation

f(x) = 8. (These solutions give the values of x for which the

shaded area is 8 m2

.)

A ď¬‚exible wire P QRS, of total length 12 metres, is bent into a three-edged

planar shape, and its ends P, S are placed against a disc of

radius 9 metres with centre O, as shown in the diagram below. (The arc

P S is not part of the wire.) The end-segments P Q and RS of the wire lie

along straight lines through O, while the arc QR forms part of a circle

with centre O and subtends an angle x (in radians) at O.

This question concerns the area A enclosed between the wire and the edge

of the disc, which is shown shaded below. This area can be expressed by

A = f(x), where

f(x)=9x(4 − 3x)(16 + 3x) / 2(2+x)^2

0 ≤ x ≤4/3

(a) (i) Plot the graph of the function f(x). Your graph should cover the

interval [0, 1.33] in the x-direction and [0, 20] in the y-direction.

(ii) By using the ‘Trace’ facility (and also, if you wish, the ‘Zoom’

facility), estimate to two decimal places the coordinates of the

point on this graph at which y = f(x) takes its maximum value.

(iii) On the same graph, plot the line y = 8. Using the ‘Trace’ facility,

estimate to two decimal places both solutions of the equation

f(x) = 8. (These solutions give the values of x for which the

shaded area is 8 m2

.)

Expert's answer

Unfortunately, your question requires a lot of work and cannot be done for free. Submit it with all requirements as an assignment to our control panel and we'll assist you.

Need a fast expert's response?

Submit orderand get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!

## Comments

michael dickinson15.09.11, 10:00Question #4134 from robin:

I would be interested to see the answer supplied to Robin for this question as I would like to see for my own benefit how the solution is extracted is this possible please.

Kind Regards, Michael Dickinson

## Leave a comment