SIGNOS DE LAS RAZONES TRIGONOMÉTRICAS SEGÚN EL CUADRANTE. HD

Understanding Trigonometric Ratios in Different Quadrants

Introduction to Quadrants

• The video begins by introducing the concept of dividing the coordinate axis into four quadrants, starting from 0 degrees and moving counterclockwise.

• The first quadrant is defined between 0 and 90 degrees, the second quadrant spans from 90 to 180 degrees, the third quadrant covers 180 to 270 degrees, and finally, the fourth quadrant ranges from 270 to 360 degrees.

Signs of Trigonometric Functions in Each Quadrant

• In the first quadrant:

• Sine (sin) is positive.

• Cosine (cos) is positive.

• Tangent (tan), being sine divided by cosine, is also positive.

• In the second quadrant:

• Sine remains positive as it lies above the x-axis.

• Cosine becomes negative since it lies left of zero on the x-axis.

• Tangent turns negative due to a positive sine over a negative cosine.

• In the third quadrant:

• Both sine and cosine are negative.

• Tangent becomes positive because a negative sine divided by a negative cosine results in a positive value.

• In the fourth quadrant:

• Sine is negative while cosine is positive.

• Tangent remains negative as it’s calculated with a negative sine over a positive cosine.

Conclusion