A Thread For Questions

[khalil]

The life of a brand of TV is approximately normally distributed with a mean life of 7 years and a standard deviation of 2.5 years. If this brand of TV is guaranteed for 2 years, what percentage of original sales will require replacement within the guaranteed date?

[Flaming_Arrow]

The life of a brand of TV is approximately normally distributed with a mean life of 7 years and a standard deviation of 2.5 years. If this brand of TV is guaranteed for 2 years, what percentage of original sales will require replacement within the guaranteed date?

Pr(X<2) = -infty to 2

[khalil]

Dw my teacher told me the answer.

I did that FlamingArrow, but due to the context of the question we cannot have negative values

[Flaming_Arrow]

Dw my teacher told me the answer.

I did that FlamingArrow, but due to the context of the question we cannot have negative values

err the way i was taught was to ignore the context

[khalil]

you can't have negative years

[naved_s9994]

Can anyone explain truetears method by one example please, thank-you!

Ah right ok.  That makes so much more sense now. 

*face palm*  I think I think people reading this for the first time will probably think that I'm not a genuine Methods student lol.

And just one more question, with general solutions, all you do is:

1.  For sin and cos, you add to the period.
2.  For tan, you add to the period.

Right?

Nearly correct, you don't add it to the period.

For cos and sin functions the way I do the general solutions is:

Let one of the solutions be and other other solution be

Thus the general solution would be where or where

This applies to both sin and cos functions.

For tan function you only need to find one solution, let this solution be c.

Thus general solution would be where

[naved_s9994]

Also are these possible to be asked in an Exam 1?

[TrueTears]

Also are these possible to be asked in an Exam 1?

Yes they are.

Can anyone explain truetears method by one example please, thank-you!

I'll make one up.

Consider: Find the general solution to



Now the first solution would be

Another solution would be

Thus the general solution would be , where

[naved_s9994]

Also are these possible to be asked in an Exam 1?

Yes they are.

Can anyone explain truetears method by one example please, thank-you!

I'll make one up.

Consider: Find the general solution to



Now the first solution would be

Another solution would be

Thus the general solution would be , where

So is it that you give  the first two solutions? always

[TrueTears]

Also are these possible to be asked in an Exam 1?

Yes they are.

Can anyone explain truetears method by one example please, thank-you!

I'll make one up.

Consider: Find the general solution to



Now the first solution would be

Another solution would be

Thus the general solution would be , where

So is it that you give  the first two solutions? always

Nope it can just be any different form of the solutions, but the 'basic' solutions must be different.