The value of the Integral Hint: p/2 (ax3 -p/2 cos x + b sin x + c)dx, depends on how many parameters among (a , b , c). Integral of an odd function over the interval [-a,a] is zero

x3 odd , sinx odd will become zero only c will remain in integral.

x^3 is odd--->0
sinx is odd--->0
only c will left in integration in integration, hence it depends only on c.

Sher Mohammad
B.Tech, IIT Delhi