problem 1:
problem 2 :
please write the full solutions because i'm a integration newbie
and a very happy christmas and new year,from India
Using the cos(A+B) identity..
Using
gives an incorrect answer for the area between the curve and the x-axis,
since the graph of the function crosses the x-axis twice between and
Hence, the x-axis crossing points are at
and at
Inverting the negative sign for the integral in the middle part, the area is
which gives