this variable is undefined

[JPark61]

please help me why it does not work..

[Fred_Kohlhepp]

You've not learned that all of the constraints have to come after the "given" statement?  Where is "Find"?

Go read the help files about how to set up a solve block!

Or are you just dumping on this forum?

[JPark61]

how can i solve range problem.

[-MFra-]

[JPark61]

i have a question so only i want to find d.1 d.2.

all variables are a constant value.

so do I have to change d.a=0.1 not :=

[-MFra-]

Hi,

the Ks are all uppercase or lowercase.....

 

[JPark61]

Thank you!!

can you send me a file??

why my computer does not work

[-MFra-]

[JPark61]

thank you

but why d.a d.b is not corret it should be 0.1 and 0.1

[Werner_E]

If ALL of your used variables have to be constant (even q=100) and you only want to vary d1 and d2m then you are asking for the impossible. There is a linear relationship between d1 and d2 and to fulfill your equation at least one of the two must be negative. So they can't be both in the range from 0 to 0.3.

[JPark61]

HOW about this one?

q is not constant value.

[Werner_E]

---

@JPark61 wrote:

HOW about this one?

q is not constant value.

---

This is exactly what MFra already had shown quite a while ago.

If q is variable, too, you have a myriad number of solutions. And if you chose a q value for which a solution exists, there usually exist an infinite number of additional solution for d1 and d2.

So you have some additional degrees of freedom.

Some exemple:

q=10, d1=0.1, d2=0.121

or

q=10, d1=0.15, d2=0.071

or

q=10, d1=0.2, d2=0,021

etc.

Here is the formula where you can calculate d2 if q and d1 are given: