Function Graphs
Plot and explore the six trigonometric functions interactively. Switch between sin, cos, tan, csc, sec, and cot to see their curves, periods, and asymptotes. Drag the angle slider or type a value to mark any point on the graph and read its exact function value. Toggle between degrees and radians, pan across the x-axis by dragging, and zoom with the mouse wheel to study local behavior. Useful for understanding periodicity, amplitude, domain restrictions, and the relationship between an angle and its function value.
Signs by Quadrant
Discover why each trigonometric function is positive or negative in each of the four quadrants of the coordinate plane. Click any quadrant to see how the signs of x and y coordinates determine the sign of sin, cos, tan, and their reciprocals. Includes the classic ASTC mnemonic ("All Students Take Calculus") and step-by-step mathematical reasoning for every function-quadrant combination. Essential for solving trig equations, simplifying expressions, and building intuition about the unit circle.