MAT 266 Lecture Notes - Lecture 7: Pythagorean Theorem
Document Summary
Group 4: used for integration of tan and cot to an even power** Distribute the (-) to each term (sec2(x) and the -1) = tan2(x)sec2(x) - sec2(cid:894)x(cid:895) + dx u = tan(x), du= sec2(x)dx. = u2du tan(x) + x + c. = 1/3 tan3(x) tan(x) + x + c. Sec(cid:894)x(cid:895)dx = ln |sec(cid:894)x(cid:895) + tan(cid:894)x(cid:895)| + c. Csc(cid:894)x(cid:895)dx = ln |csc(cid:894)x(cid:895) cot(x)| + c. Example: prove that tan(cid:894)x(cid:895)dx = ln |sec(cid:894)x(cid:895)| + c. Substitution x=asin , - x=atan , - (cid:888) (cid:888)< < x=asec , 0 < (cid:888) (cid:888) (cid:888) < (cid:889) (cid:888) Call x = 2sin , - (cid:888) . Call dx = 2cos equation 2 (cid:888) (cid:890) (cid:888) (cid:890) (cid:890) . Using both equation 1 and 2 (cid:887) (cid:890) (cid:887) (cid:890) (cid:888) . equation 1 (cid:888) (cid:890) (cid:888) (cid:888) . the 2cos are canceling with each other (cid:887) (cid:887) (cid:890) cot( (cid:4667) + c (***) find the cot ( (cid:4667) in the (***) equation above.