Evaluate ∫secx(5secx+8tanx) dx. Here C is the constant of integration.

We have the integral:
[tex]\int secx(5secx+8tanx)dx[/tex]We expand the expression:
[tex]\int5sec^2x+8tanxsecxdx[/tex]Using trigonometric identities we can rewrite:
[tex]\int\frac{5+8sinx}{cos^2x}dx[/tex]We expand again:
[tex]\int\frac{5}{cos^2x}+\frac{8sinx}{cos^2x}dx[/tex]We separate the integral as:
[tex]\int\frac{5}{cos^2x}dx+\int\frac{8sinx}{cos^2x}dx[/tex]By integration rules we have that:
[tex]\int\frac{5}{cos^2x}dx=5tanx[/tex]And
[tex]8\int\frac{sinx}{cos^2x}dx=8secx[/tex]All together:
[tex]5tanx+8secx+C[/tex]This would be the answer with the constant c.
[tex]5tanx+8secx+C[/tex]