How do you find the two quadrants that #theta# could terminate given #sintheta=-3/sqrt10#?

1 Answer
Jim G.
May 13, 2017

#"third and fourth"#

Explanation:

#"for " 180^@ < theta < 0^@" that is first/second quadrants"#

#"then " sintheta" has a "color(blue)"positive value"#

#"for " 360^@ < theta < 180^@" that is third/fourth quadrants"#

#sintheta" has a "color(blue)"negative value"#

#"since "sintheta=-3/sqrt10#

#"then "theta" will terminate in the third or fourth quadrant"#

#"the acronym " ASTC" indicates which ratio is "color(red)"positive"#
#"in the relevant quadrant"#

#A" indicates All trig ratios in first quadrant"#

#S" indicates Sine ratio in second quadrant"#

#T" indicates Tangent ratio in third quadrant"#

#C" indicates Cosine ratio in fourth quadrant"#

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