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The cosine of an angle is the adjacent side of the angle of a triangle divided the hypotenuse. If you plot the adjacent side as x on an x -y graph, for negative angles less than 90 degrees the adjacent side is positive and the hypotenuse is always positive, so you get a positive.
The cosine is positive int e upper right and lower right quadrants
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What Is the value of cos?
Cos is the ratio between adjacent side (of the given angle thieta) to the hypotenuse of the triangle.
What is cos(22 degrees)?
cos(22) is a trigonometric ratio and, if the angle is measured in degrees, its value is 0.9272
What is the exact value of cos 120?
negative one half
What is a quadrantal angle?
A Quadrantal angle is an angle that is not in Quadrant I. Consider angle 120. You want to find cos(120) . 120 lies in quadrant II. Also, 120=180-60. So, it is enough to find cos(60) and put the proper sign. cos(60)=1/2. Cosine is negative in quadrant II, Therefore, cos(120) = -1/2.
Why is the tangent positive on quadrant III?
The tangent function is equal to the sine divided by the cosine. In quadrant III, both sin and cos are negative - and a negative divided by another negative is positive. Thus it follows that the tangent is positive in QIII.
