I'm on limits and I need some help.
Question is... Determine the Infinite Limit(so say if it's positive infinity or negative infinity).
lim of cot x as x gets close to pi.
I know you use pi/6, pi/4, pi/3, pi/2, 2pi/3, and 3pi/4 and plug that in for x, but I'm a little confused on how to do that. Do I just use 2nd tan on the calculator and plug in the pi/6, pi/4, etc? I heard second tan on a calc isn't cotangent.... help!
2007-09-04 14:46:27 · 5 answers · asked by orbit 2 in Science & Mathematics ➔ Mathematics
The best way to work it out is to think about it.
cot x = cos x / sin x
At π, cos x reaches its minimum value of -1, and sin x goes from positive to 0 to negative.
So just before π we have -1 / (small positive) and just after π we have -1 / (small negative).
So the limit on the left of π is -∞, and the limit on the right is +∞.
2007-09-04 14:54:11 · answer #1 · answered by Scarlet Manuka 7 · 0⤊ 0⤋
Are you just asking how to calculate the cotangent of an angle using your calculator? Remember the cotangent is just the reciprocal of the tangent. So find the tangent and take the reciprocal.
By the way, this particular limit is going to be different depending on which direction you're coming from.
2007-09-04 21:54:57 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Don't use a calculator (well, except the thing that comes with windows) so I can't help you with that. You could just take the tan and then do (1/x). That will also give you the cot.
2007-09-04 21:56:12 · answer #3 · answered by Captain Mephisto 7 · 0⤊ 0⤋
cot(x) = cos(x)/sin(x) as x -> pi sin(x) --> 0, cos(x) --> -1 so the lim (cot(x)) --> - infinity
Can't do this on a calculator, you ahve to understand the math.
2007-09-04 21:54:02 · answer #4 · answered by nyphdinmd 7 · 0⤊ 1⤋
I guess it should be negative infinity.
2007-09-04 21:55:14 · answer #5 · answered by Josh 3 · 0⤊ 0⤋