Thread: Maths.....

The actual function is defined in ranges and the value of Tmax is the what the function is at time t=0. 61/4 like they said. I see no trouble with it.

Originally Posted by niftyshaving

Oh bother something is missing these are inconsistant.
Tmax = a constant.
t²-9t+61/4 = a variable function of time.

The problem as stated is tangled or missing something.

If I untangle this a bit we know that Tmax is established
at zero hour... so,

Tmax = t²-9t+61/4
Tmax = 0²-(9*0)+(61/4) = 61/4

And if we read the variable function of time differently
in a more general way. "T" is Temp and "t" is time.
T =t²-9t+61/4
we now have a relationship of temperature versus time
(Temp is now a function of time)....
and can do some simple test plots with pen and paper for
time increasing from zero in 10 minute bits to understand
what we need to solve for.

In math when something is "constant" it never changes.
If the variable is Tmax then there is a problem. If the
variable is "T sub max" then this is a point value in the
continuous set of possible values.

Originally Posted by niftyshaving

If I untangle this a bit we know that Tmax is established
at zero hour... so,

Tmax = t²-9t+61/4
Tmax = 0²-(9*0)+(61/4) = 61/4

And if we read the variable function of time differently
in a more general way. "T" is Temp and "t" is time.
T =t²-9t+61/4
we now have a relationship of temperature versus time
(Temp is now a function of time)....
and can do some simple test plots with pen and paper for
time increasing from zero in 10 minute bits to understand
what we need to solve for.

In math when something is "constant" it never changes.
If the variable is Tmax then there is a problem. If the
variable is "T sub max" then this is a point value in the
continuous set of possible values.

Ok. I understand and I agree. "Tmax" is a misleading function name. T(t) would be better. And Tmax would be T(0). Probably a misnomer on the part of the teacher or the OP.

Nope I wrote the question out word for word as it said.

T(max)

I also said she was a terrible maths teacher.
We`re now studying calculus. she wrights it on the board we copy it and we leave the room and nothing has sunk in.

Originally Posted by BigIan

T(max)
I also said she was a terrible maths teacher.

Temperature as the function of max? That makes even less sense. Unless Max is the blue leprechaun that operates the Leonard's "Make the chillyness a paraboloidical function just for the heck of it"-machine... I guess it was your teacher then.

Sorry to hear you ended up with bad mathmistress. Maybe you could get somebody to tutor you privately?

Originally Posted by BigIan

a) what is the value of t max.

T-max's usefulness in relation to other T's, along with it's perceived value will determine it's value.

Originally Posted by BigIan

b Use the method of completing the square to determine:

i)the minimum temperature reached during the maintenance period.

ii)the amount of time the system was switched off for maintenance.

i. The minimum temperature reached and the time switched off for maintenance depends highly on whether the maintenance personnel are paid hourly or are salaried. If the workers are paid hourly, the off time as well as the minimum temperature would be much longer and thus colder. If the workers are salaried, the off time would've been shorter so as to maintain a more comfortable temperature in the room during maintenance.
The amount of actual maintenance performed depends upon whether the contractors were union or not.