# Revision history [back]

### theta=f(x), theta.derivative(x) doesn't work

How can you defined a variable as some function of another variable without specific definition? For example, I can you define theta as some function of x and then differentiate the 'sin(theta)' by x?

The following is my code that doesn't work. I couldn't find how to fix it in reference manuals. Any help will be appreciated.

var('theta, y, f')

y=sin(theta) ; theta=f(x);

y.derivative(x)

### theta=f(x), theta.derivative(x) doesn't workA simple problem related to symbolic calculation

How can you defined a variable as some function of another variable without specific definition? For example, I can you define theta as some function of x and then differentiate the 'sin(theta)' by x?

The following is my code that doesn't work. I couldn't find how to fix it in reference manuals. Any help will be appreciated.

var('theta, y, f')

y=sin(theta) ; theta=f(x);

y.derivative(x)

### A simple problem related to symbolic calculation

How Could anyone let me know how you can you defined define a variable as some function of another variable without specific definition? For example, I how can you define theta as some function of x and then differentiate the 'sin(theta)' by x?

The following is my code that doesn't work. I couldn't find how to fix it in reference manuals. Any help will be appreciated.

var('theta, y, f')

y=sin(theta) ; theta=f(x);

y.derivative(x)

 4 retagged rws 1059 ●1 ●16 ●37 http://google.com/+Ral...

### A simple problem related to symbolic calculation

Could anyone let me know how you can define a variable as some function of another variable without specific definition? For example, how can you define theta as some function of x and then differentiate the 'sin(theta)' by x?

The following is my code that doesn't work. I couldn't find how to fix it in reference manuals. Any help will be appreciated.

var('theta, y, f')

y=sin(theta) ; theta=f(x);

y.derivative(x)

 5 retagged rws 1059 ●1 ●16 ●37 http://google.com/+Ral...

### A simple problem related to symbolic calculation

Could anyone let me know how you can define a variable as some function of another variable without specific definition? For example, how can you define theta as some function of x and then differentiate the 'sin(theta)' by x?

The following is my code that doesn't work. I couldn't find how to fix it in reference manuals. Any help will be appreciated.

var('theta, y, f')

y=sin(theta) ; theta=f(x);

y.derivative(x)