- #1

physstudent1

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**[SOLVED] Solving differential equations**

## Homework Statement

Find the solution:

dy/dx = (1+y^2)/(1+x^2)

hint: there is a formula tan(a + b) that will simplify your answer.

y(0)=1

## Homework Equations

## The Attempt at a Solution

I separated the variables and integrated ending up with

arctan(y)=arctan(x)+c

I do not see how to take this to the answer below. I understand how to use the formula they gave me in the hint but I do not see how it applies here...

the answer is

y=(1+x)/(1-x) this problem is from my exam review we have the solutions but not how to get them...