The function is given as,
y = ∫ −π 2 π 2 sin 7 x dx
We have to calculate the integral of y.
Consider g( x )= sin 7 x.
g( x )= sin 7 x g( −x )= sin 7 ( −x ) g( −x )= ( sinx ) 7 ( −1 ) 7 g( −x )=− sin 7 x
It can be observed that g( x )=g( −x ). So, sin 7 x is an odd function.
Use property of odd functions ∫ −b b g( x )dx =0 if g( −x )=−g( x ) or g( x ) to solve integral.
y= ∫ −π 2 π 2 sin 7 x dx =0
Thus, the value of integral is 0.