9 replies to this topic

[panda2]

I will writting a program to cplua,According to this formula

x-4*z=2+x

x=?

Thank you for helping me

[piu58]

The formula is only valid for z=-0.5. It is valid for every x then.

[panda2]

The formula is only valid for z=-0.5. It is valid for every x then.

Hi،Thanks, yes, I made a mistake,please guide me for writting this formula,

x=tonumber(input("x?"))
y=tonumber(input("y?"))
x-4*z=2*x+y
What do I need to write to get z ?

[piu58]

This formula is equivalent to z=-0.25(x+y)

You don't need a program for that.

[panda2]

This formula is equivalent to z=-0.25(x+y)

You don't need a program for that.

Tnx,However, when the formula is larger, it is no longer possible to bring the unknown one first

[piu58]

You always may try to resolve the formula partially to the variable looked for. And the use a starting value and calculate the formula again and again until it converges. If it diverges, resolve to another value of the variable looked for.

[panda2]

You always may try to resolve the formula partially to the variable looked for. And the use a starting value and calculate the formula again and again until it converges. If it diverges, resolve to another value of the variable looked for.

Thank you, but this is difficult, for example in the formula if x is unknown, whether simple formula that breaks down,Then this method will not be easy; ; I want to answer every variable in the formula.

for exp: (btop×ttop)+(x×tmid)=(bbot×tbot)+((hmid-x)×tmid)

x=?

How to write this formula in the program of cplua or basic

Edited by panda2, 02 February 2018 - 12:22 AM.

[piu58]

Again simple. You dnon't need a claculator program but a deeper understanding of mathematics.

For clarity I replaced

btop a

ttop b

tmid c

bbot d

tbot e

hmid f

tmig g

 

 

Your formula rewrites as

 ab+xc = de+gf-gx

 

and resolves to

x = (de+gf-ab) / (c+g)

 

(if I have done all correctly).

[panda2]

Again simple. You dnon't need a claculator program but a deeper understanding of mathematics.

For clarity I replaced

btop a

ttop b

tmid c

bbot d

tbot e

hmid f

tmig g

 

 

Your formula rewrites as

 ab+xc = de+gf-gx

 

and resolves to

x = (de+gf-ab) / (c+g)

 

(if I have done all correctly).

Thank you, your method is correct, but anyway, there must be a way to get the unknown as a solve of classpad, instead of simplifying the formula.If the formula is long, this simplifies the problem

Edited by panda2, 02 February 2018 - 05:28 PM.

[panda2]

I found the solution

ClrText
print"hello"
input x
input z
Print solve(z=x+y,y)