tangent of arcTangent

[zaki_Khan]

i try to test the tangent of arctangent of x normally its aqual to x but when i run i found another value so why ?

and why the tan(arcTang(x)) not equal to x ?

[JensG69]

Think DATAflow: Your VI calculates the arctangent of the tangent of x.

[alexderjuengere · Accepted solution]

[JensG69]

Same here, at least halt of it, the upper part is the arctan(tan(x)) and hence another calculation than the formula node.

[alexderjuengere]

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@JensG69 wrote:
Think DATAflow: Your VI calculates the arctangent of the tangent of x.

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@JensG69 wrote:
Same here, at least halt of it, the upper part is the arctan(tan(x)) and hence another calculation than the formula node.

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sorry for being a troll...

[JensG69]

I'm sorry for my previous reply, I mis-read the question of the OP.

@zaki_Khan: tan(arctan(x)) = x is only valid for x-values (in rad) between -Pi/2 .. Pi/2 (or -90° .. 90° in degree).

Regards

[altenbach]

All trigonometric functions are periodic. This means for every Y, there is an infinite number of valid X values. The inverse function will give you an X that is normalized into a defined range. Check the help what the normalized range is (e.g. 0..180, -90..90, etc. or the equivalent in radians).

[altenbach]

Also don't forget the Two input inverse tangent function Very useful because it maps into all four quadrants.

[zaki_Khan]

thank you

[zaki_Khan]

thanks ,