I know tan = y/x and cot = x/y. But I have some trouble on figuring whether x or y is negative when the number in the parentheses is negative. For example, take: tan -(5/4) or cot -(3/7) . How can i figure out whether x or y is negative?
2007-12-10 13:53:26 · 3 answers · asked by Just Me 2 in Science & Mathematics ➔ Mathematics
Oh..my teacher put that on the test with no clues and i got marked off for the wrong answer.
2007-12-10 14:17:33 · update #1
You need another clue from somewhere, like which quadrant the angle is in.
2007-12-10 14:03:41 · answer #1 · answered by Helmut 7 · 1⤊ 0⤋
ok, say you are trying to draw a triangle to display [tan -(5/4)],
it will have 2 answers...and they are in opposite quadrants
you will have y = -5 and x = 4 representing one triangle
and you will have y = 5 and x = -4 representing another triangle
(by x and y, i just mean the diff sides of the triangle since it's hard to draw it on yahoo)
the same thing goes with the other equation...you will have 2 answers
if you ever take physics and use trig to determine directions of things like forces...you have to check to make sure your answer makes sense...because your calculator might tell you the opposite quadrant
if you have a problem that shows up as tan -(5/4) ...the calculator will pick a quadrant and solve the answer for it...sometimes you need to do 180 - [your answer] to get the right thing you're looking for...so be careful about that
hope this helps :-)
2007-12-10 22:24:00 · answer #2 · answered by Elfy 2 · 1⤊ 0⤋
You can't, you must be going about the question the wrong way. What is the entire problem you are trying to solve?
2007-12-10 21:59:18 · answer #3 · answered by Zac B 1 · 0⤊ 0⤋