Which quadrants are trig functions positive

Finally, in the fourth quadrant, the cosine of any angle is positive, whereas the sine and tangent of any angle is negative. We can therefore conclude that the sine function is positive in the first and second quadrants.

The cosine function is positive in the first and fourth quadrants. And the tangent function is positive in the first and third quadrants. Summarizing this, we see that all three trigonometric functions are positive in two quadrants. Let's see how the trigonometric ratios are defined using a particular example. Example of a trig ratio where the angle is greater than 90 o. Observe for the example above, that our angle was in the second quadrant.

Also notice that in the second quadrant, the y -value is positive. In the second quadrant, x is always negative. We use this diagram to remember what ratios are positive in each quadrant. We can remember it using:. Drag the point P around the curve into all 4 quadrants and observe the sin, cos and tan ratios that result.

Notice in particular the ratios which are positive in each quadrant. Friday math movie - Trigonometric Strange Attractor Evolution. Coterminal angle by anhy [Solved!

Is degrees considered to be in the 3rd or the 4th quadrant? Solving a triangle by Deyanza [Solved! Coterminal angle by Bridgett [Solved! When an angle lies along an axis, the values of the trigonometric functions are either 0, 1, -1, or undefined.

When the value of a trigonometric function is undefined, it means that the ratio for that given function involved division by zero. Below is a table with the values of the functions for quadrantal angles. The points at which the values of a function are undefined are technically not in the domain of that function.

Therefore, the domain of sine and cosine is all real numbers. SparkTeach Teacher's Handbook.