dy/dx = sin(xy), y(0) = 1

Using Euler method to find an approximate value......

When finding the approximate value, do I use sin in radians or in degrees???

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- May 11th 2011, 04:17 AMbakchormeeEuler method
dy/dx = sin(xy), y(0) = 1

Using Euler method to find an approximate value......

When finding the approximate value, do I use sin in radians or in degrees??? - May 11th 2011, 04:54 AMAckbeet
You should assume radians. Radians are, in general, superior.

- May 11th 2011, 04:59 AMHallsofIvy
Especially when working with Calculus and Differential Equations. The laws $\displaystyle \frac{d(sin(x))}{dx}= cos(x)$ and $\displaystyle \frac{d(cos(x))}{dx}= -sin(x)$ are only true for x in radians.

(In fact, the definitions of sine and cosine that you should be using at this point do not require that x be an angle at all- should not even**have**units just as you don't worry about the units for "x" in $\displaystyle x^2$- but in order to connect to the "old" trigonometric definitions (and keep the engineers happy), we can think of x as being in "radians".)