### Home > CALC > Chapter 10 > Lesson 10.3.1 > Problem 10-115

10-115.

When *t* = 0 or cos(*πt*) = 0.

*a*(*t*) = cos(*πt*) – *t*(*π*)sin(*πt*)

Use integration by parts. Let *f* = *f* and *dg* = cos(*πt*)*dt*.

Solve for *C* given *x*(0) = 5.

10-115.

When *t* = 0 or cos(*πt*) = 0.

*a*(*t*) = cos(*πt*) – *t*(*π*)sin(*πt*)

Use integration by parts. Let *f* = *f* and *dg* = cos(*πt*)*dt*.

Solve for *C* given *x*(0) = 5.