The goal of this problem is to evaluate 121 2 de using trig substitution Click on Part 1 to open the section Enter your answers for the three steps in Part 1 to set up the trig substitution then click on Submit Answers Once your answers are all correct you will be able to open Part 2 to take the value of the trig integral and substitute back in terms of Part 1 The Trig Substitution Setup Give an appropriate trig substitution in the form x f t where t represents 8 I dx dt Now substitute and simplify to get a trig integral in terms of t The trig integral should no longer involve a square root 121 x dx dt