Question

8. If a and b are respectively the sum and product of coefficients of terms in the expressionx2 + y2 + z2 - xy - yz – zx , then a + 2b =(a) o(b) 2(c) - 2(d) -1​

Answer 1

a = sum of coefficients = 1+1+1-1-1-1=0

b = Product of coefficients = 1×1×1×(-1)×(-1)×(-1)= -1

Now Substitute the value of a and b in a+2b, we get

0 + 2(-1)= -2

(c) -2 is correct