MATH 101 Lecture Notes - Lecture 14: Trigonometric Substitution, Scilab
Document Summary
Math 101 lecture 14, wednesday, 4th february, 2015. Last time we saw how to integrate various trigonometric integrals. We will now use the skill for more trickier substitutions. / x2 dx hence 9cos2 x = 9 9si n2 x. So if we write x=3sint so dx = 3cost dt, then we can write . Dx/ since 1+tan2 y=se c2 y ,it follows that =2 secy. Now substituting u = sin ,du=cos d , we get . In general, the substitutions we will use are: (cos /4si n2 )d x=asint when because a2 a2 si n2 x=co s2 x x =atant when etc x = asect when etc.
