Put a=1,b=−1 in (a2+b2)(−a2+b2)
={12+(−1)2}{−(1)2+(−1)2} [∵(−1)2=1]
=(1+1)(−1+1)
=2×0=0
Hence, (a2+b2)(−a2+b2)=0
If a + b = 10 and ab = 16, find the value of a2−ab+b2 and a2+ab+b2.