If ` a = (5-sqrt21)/2 `then the value of `a^3 + a^-3 - 5a^2 - 5a^-2 + a + a^-1` is

If x=(1)/(sqrt(5)-2) , find the value of x^(3)-3x^(2)-5x+3 .

If x=(5-sqrt(21))/(2), then the value of (x^(3)+(1)/(x^(3)))^(2)-5(x^(2)+(1)/(x^(2)))+(x+(1)/(x))

If | vec a| = | vec b | = 1 and | vec a + vecb | = sqrt3 , then the value of (3 veca -4 vec b ).(2veca +5vec b ) is : a) -21 b) -(21)/(2) c) 21 d) (21)/(2)

If a = (sqrt5 +1)/(sqrt5-1) and b = (sqrt5-1)/(sqrt5+1) then find the value of (5a^(2) -3ab +5b^(2))

The value of (3+sqrt(5))^2 (3-sqrt(5))^2 is:

If 5sqrt(5) xx 5^(3) /5^(-3/2) = 5^(a +2) then the value of a is

If x=3sqrt(5)+2sqrt(2) and y=3sqrt(5)-2sqrt(2) , then the value of (x^(2)-y^(2))^(2) is

If a=(sqrt(5)+1)/(sqrt(5)-1) and b=(sqrt(5)-1)/(sqrt(5)+1), the value of ((a^(2)+ab+b^(2))/(a^(2)-ab+b^(2))) is (3)/(4) (b) (4)/(3)(c)(3)/(5)(d)(5)/(3)