SOLUTION: tanx-sqrt(3)<=0

Algebra ->  Trigonometry-basics -> SOLUTION: tanx-sqrt(3)<=0      Log On


   



Question 710041: tanx-sqrt(3)<=0
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
tan%28x%29-sqrt%283%29%3C=0
Is this the whole problem? I suspect that there may be something about finding solutions from within some set of numbers, like between 0 and 2pi.

Adding the square root to each side:
tan%28x%29%3C=sqrt%283%29
sqrt%283%29 is a special angle value for tan. The reference angle is pi%2F3. Since the period of tan is just pi, the set of angles that makes tan%28x%29=sqrt%283%29 would be:
x+=+pi%2F3+%2B+pi%2An (where "n" is any integer)

For the "less than" part of the inequality we should realize:
  • All negative tan's will be less than a positive number like sqrt%283%29. Since tan is negative in the 2nd and 4th quadrants, all angles which terminate in either of these quadrants will be solutions to this inequality.
  • For positive tan's, the tan value grows as the reference angle grows and vice versa. So for positive tan's that are less than sqrt%283%29 we want reference angles that are less than pi%2F3. IOW: We want a reference angle between 0 and pi%2F3 in quadrants where tan is positive (1st and 3rd).
  • If tan(x) is zero then it would be less than sqrt%283%29. So x's that make tan zero would also be solutions to the inequality:
    x+=+0+%2B+pi%2An
To summarize, the solutions to your inequality are:
  • x+=+pi%2F3+%2B+pi%2An (because they make tan(x) equal to sqrt%283%29
  • x+=+0+%2B+pi%2An (because they make tan(x) equal to 0 (which is less than sqrt%283%29)
  • x = any angle that terminates in the 1st or 3rd quadrant with a reference angle less than pi%2F3 (because they make tan(x) a positive number less than sqrt%283%29
  • x = all angles that terminate in the 2nd or 4th quadrant (because they make tan(x) negative (which is less than sqrt%283%29))