Trigonometric Substitution Trigonometric Substitution Part 1 of 6 Evaluate dx J (x² - 6x +18)² First, write the expression x² - 6x + 18 in appropriate form so that trigonometric substitution can be performed. x² - 6x + 18 = (x − 3)² +9 (x − 3)² +9 Part 2 of 6 Given that x² - 6x + 18 = (x − 3)² + 9, write the appropriate trigonometric substitution. Use for the substitution variable. X =