finding the minimum

[enott312]

I have a problem in my exam revision and I am getting stuck.

The problem is basically as follows

A hiker is walking from checkpoint 1 to checkpoint 2 in the mountains, x km apart. The time taken for the journey, t, in hours is given by the following equation

Find the minimum time that the journey can take.

I know that you need to solve where dt/dx = 0.

and

When I solve for x I get 13 and then subbing into equation 1, t is also 13 (approx).
The answer that I am supposed to get is t = 5 (according to the answer sheet).

Can someone point out where I am going wrong?

 

[enott312]

I have a problem in my exam revision and I am getting stuck.

The problem is basically as follows

A hiker is walking from checkpoint 1 to checkpoint 2 in the mountains, x km apart. The time taken for the journey, t, in hours, is given by the following equation

I know that you need to solve where dt/dx = 0.

This is the working I do:

Subbing this back into the original equation does not work as you then need to take SQRT (-11.53) and in the course that I am doing this in, we do not use i​. Where am I going wrong?

 

[Ishuda]

I have a problem in my exam revision and I am getting stuck.

The problem is basically as follows

A hiker is walking from checkpoint 1 to checkpoint 2 in the mountains, x km apart. The time taken for the journey, t, in hours, is given by the following equation

I know that you need to solve where dt/dx = 0.

This is the working I do:

Subbing this back into the original equation does not work as you then need to take SQRT (-11.53) and in the course that I am doing this in, we do not use i​. Where am I going wrong?

Your work - I assume they are images - are not showing up. Can you type them in or present them in some other way?

 

[stapel]

A hiker is walking from checkpoint 1 to checkpoint 2 in the mountains, x km apart. The time taken for the journey, t, in hours, is given by the following equation

http://www.freemathhelp.com/forum/attachment.php?attachmentid=5566&stc=1

I know that you need to solve where dt/dx = 0.

http://www.freemathhelp.com/forum/attachment.php?attachmentid=5567&stc=1

This is the working I do:

http://www.freemathhelp.com/forum/attachment.php?attachmentid=5568&stc=1
http://www.freemathhelp.com/forum/attachment.php?attachmentid=5569&stc=1
http://www.freemathhelp.com/forum/attachment.php?attachmentid=5570&stc=1
http://www.freemathhelp.com/forum/attachment.php?attachmentid=5571&stc=1
http://www.freemathhelp.com/forum/attachment.php?attachmentid=5572&stc=1
http://www.freemathhelp.com/forum/attachment.php?attachmentid=5573&stc=1
http://www.freemathhelp.com/forum/attachment.php?attachmentid=5575&stc=1

Something is happening that is causing your uploaded images not to cache, or to be attempting to cache empty file-calls. Please reply with the typed-out text of your work. Thank you!