How would you find the exact value of the six trigonometric function of 225 degrees?

1 Answer
Nov 21, 2016

#sin(225^@)= -1/sqrt(2)color(white)("XXX")csc(225^@)=-sqrt(2)#
#cos(225^@)= -1/sqrt(2)color(white)("XXX")sec(225^@)=-sqrt(2)#
#tan(225^@)=+1color(white)("XXXX")csc(225^@)=-1#

Explanation:

#225^@=180^@+45^@#

So #225^@# has a reference angle of #45^@# in Quadrant 3 (Q III).

According to CAST,
only #tan# (and its inverse #cot#) are positive in Q III.

#45^@# is one of the standard trigonometric angles.
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