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RonnyDeKoning
tan (- alpha) and - tan alpha, what is the different between those 2 "-"'s
no difference, both are negatives.
But, I don't understand this:tan (-alpha) = -tan alpha
if alpha is in 1st quadrant - alpha is in 4th quadrant. In 4th quadrant, tan ratio is negative. hence, tan(-x)=-tan x
I don't understand.
what exactly is your doubt ?
so (tan (-x) is from the 4th quadrant and -tan x in the first, how can it be negative in the first.
a ratio can't be in any quadrant.... x is an angle, its in 1st quadrant., then tan x is positive. if x is in 1st quadrant, -x is in 4th quadrant, where tan x is negative, so, we need to bring out -*minus* sign and write tan(-x) = - tan x (....and NOT tan(-x)=tan x)
sin,cos , tan,.... are ratios...
I a making an ex: and see this: tan x = -1 <=> - tan x (pi/4) Why is the - before tan?