Question 1052983
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This problem requires:
1. Knowing how to find the reference angle of any angle.
2. Knowing what the signs of the trig ratios are in
the various quadrants.

190° is in QIII, its reference angle is 190°-180° = 10°
The cosine is negative in QIII, the cosine of 10° in positive.
So cos(190°) = -cos(10°)

290° is in QIV, its reference angle is 360°-290° = 70°
The cosine is positive in QIV, the cosine of 70° in positive.
So cos(290°) = cos(70°)

Edwin</pre>