Scratch

HD123 wrote:

I just found a glitch with a math function. The tangent of -90 will not work. I just noticed it in a project I was making. Any other math function errors?

That is strange...

I haven't noticed any other weird math errors, though.

As mathematics aluded to above, tangent is undefined at +/- 90 degrees (pi/2 in radians).  This is because the function is defined as y divided by x on a circle of radius 1.  X is zero at +/- 90 degrees, so since you can't divide by zero, tangent has to be undefined.  Here's more about it:   http://www.themathpage.com/atrig/graphs … tm#tangent

coolstuff wrote:

DB88 wrote:

As mathematics aluded to above, tangent is undefined at +/- 90 degrees (pi/2 in radians).  This is because the function is defined as y divided by x on a circle of radius 1.  X is zero at +/- 90 degrees, so since you can't divide by zero, tangent has to be undefined.  Here's more about it:   http://www.themathpage.com/atrig/graphs … tm#tangent

http://www.themathpage.com/atrig/trig_IMG/116.gif

That actually makes sense. Thanks for clearing that up!
But Google seems to think the tangent of 90 is possible.

Google is giving the answer for the tangent of 90 radians.  If you want the tangent of 90 degrees, you have to say "tan 90 degrees".  That results in tan(90 degrees) = 1.63317787 × 10^16, which is essentially infinte (or undefined).

coolstuff wrote:

DB88 wrote:

coolstuff wrote:

That actually makes sense. Thanks for clearing that up!
But Google seems to think the tangent of 90 is possible.

Google is giving the answer for the tangent of 90 radians.  If you want the tangent of 90 degrees, you have to say "tan 90 degrees".  That results in tan(90 degrees) = 1.63317787 × 10^16, which is essentially infinte (or undefined).

Thanks again 

See, I'm a newbie when it comes to trigonometry - one of my projects used it (and I only just understand what it's doing  ), but that's pretty much the extent of it. I only just learned what Sine, Cosine, and Tangent were (in detail) today during math 

No problem     One more bit of knowledge to drop on you (since you are just starting with trig):  You already know that a circle can be divided up into 360 "degrees".  But what is a "radian"?  Well, imagine you have a circle with a radius of "1".  Now say you take a piece of string that is "1" long and you carefully lay it along the circumference of the circle.  Next, you draw a line from the center of the circle to each end of the string.  The angle included between those two lines is defined as 1 radian.  It turns out that "pi" radians = 180 degrees.  Another way of saying it is that 2*pi radians = 360 degrees.  You probably know that the circumference of a circle is 2*pi*r.  That is because you can calculate the length of "string" (also called the arc length) for given angle in radians as s = r*theta, where "s" is the arc length, "r" is the radius, and "theta" is the angle expressed in radians.  So now, knowing that, you can see that the "arc length" of a full circle (which is its circumference) can be calculated by using the s=r*theta equations by s=r*(2*pi), which gives you the familiar equation for the circumference of a circle (2*pi*r)!

One more thing ... to convert degrees to radians, multiply the degrees by pi and divide by 180.  To convert radians to degrees, multiply by 180 and divide by pi.