for a triangle in standard position, sinC = y/r
since r is always positive, you must have y>0. That is QI and QII.
Since cosC = x/r, you must have x<0, so QII
You have a 7-24-25 triangle, so the terminal point of the hypotenuse lies at (-7,24).
If you are new to this, just recall that it is almost always a good place to start by drawing the triangle in standard position, and recalling that
sinC = y/r
cosC = x/r
tanC = y/x
That will get you 90% of the way there every time.
Consider ∠C such that sin C = 7/25
a) What are the possible quadrants in which ∠C may lie?
b) If you know that cos C is negative, how does your answer to part a) change?
c) Sketch a diagram to represent ∠C in standard position, given that the condition in part b) is true.
d) Find coordinates of a point P on the terminal arm of ∠C.
e) Write exact expressions for the other two primary trigonometric ratios for ∠C.
- I need help getting started in the right direction. Please be specific as I am new to trig.
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