If z= (y-a x)+ (y+a x) , ^2 z x^2 -a^2 ^2 z y^2 is equal to

Step-by-step solution

We have, aligned & z= (y-a x)+ (y+a x) & z x =-a (y-a x) (y-a x)+a ^2(y+a x) & ^2 z x^2 =-a [-a (y-a x) ^2(y-a x) . & . ^2(y+a x) (y+a x) -a ^3(y-a x) ]+2 a^2 & Similarly ^2 & ^2 z y^2 = (y-a x) ^2(y-a x) & + ^3(y-a x)+2 ^2(y+a x) (y+a x) & ^2 z x^2 -a^2 ^2 z y^2 =0 aligned