why (-a) raise to power b is equal to a raise to power b
(-a) raise to power b =
(a raise to power b) when b is even
-(a raise to the power b) when b is odd
Example:
(-2) raise to power 3 = (-2)*(-2)*(-2)=-8=-(2 power 3)
(-2) raise to power 4 = (-2)*(-2)*(-2)*(-2)=16=(2 power 4)
Hope you get it!!!