Trigonometric Function Trigonometric Functions (Right Triangle) Special Angles Trigonometric Function Values in Quadrants II, III, and IV Examples: Example2: Example: 3: Unit Circle Addition Formulas: cos(X+Y) = cosXcoxY – sinXsinY cos(X-Y) = cosXcoxY + sinXsinY sin(X+Y) = sinXcoxY + cosXsin sin(X-Y) = sinXcoxY – cosXsinY tan(X+Y) = [tanX+tanY]/ [1– tanXtanY] tan(X-Y) = [tanX-tanY]/ [1+ tanXtanY] cot(X+Y) = [cotX+cotY-1]/ [cotX+cotY] cot(X-Y) = [cotX+cotY+1]/ [cotX-cotY] Sum to Product Formulas: cosX + cosY = 2cos [(X+Y) / 2] cos[(X-Y)/2] sinX + sinY = 2sin [(X+Y) / 2] cos[(X-Y)/2] Difference to Product Formulas cosX - cosY = - 2sin [(X+Y) / 2] sin[(X-Y)/2] sinX + sinY = 2cos [(X+Y) / 2] sin[(X-Y)/2] Product to Sum/Difference Formulas cosXcosY = (1/2) [cos (x-Y) + cos (X+Y)] sinXcoxY = (1/2) [sin (x+Y) + sin (X-Y)] cosXsinY...