If `a = (sqrt3 + sqrt2)/(sqrt3-sqrt2)` then the value of `2a^4 - 21 a^3 + 12 a^2 - a + 1` is

If a=(sqrt(3)+sqrt(2))/(sqrt(3)-sqrt(2)) then the value of 2a^(4)-21a^(3)+12a^(2)-a+1 is

1/(sqrt3 + sqrt2) + 1/(sqrt3 -sqrt2)=

(sqrt3+sqrt2)^(4)- (sqrt3-sqrt2)^(4) =

If a= (sqrt3 - sqrt2)/(sqrt3 + sqrt2), b = (sqrt3 + sqrt2)/(sqrt3 - sqrt2) then what is the value of a^2/b+b^2/a ?