Question

MCQ:
Q1.Which of following is not a polynomial?
a)x^3+√3x+5 b)x^3+√2x+6 c)x^2-3x+2 d)(x-1) (x+1)

Q2. If x/y + y/x= -1 (x,y isn't zero), then value of x^3-y^3
a)1 b)-1 c)0 d)1/2

Q3.One of factors of (25x^2-1)+(1+5x^2) is-
a)5+x b)5-x c)5x-1 d)10x

A little explanation will be appreciated..THNKS

Answer 1

according to me the answer to the first one should be d)
the answer to the second one is:-
x/y+y/x=-1
x^2+y^2=-x*y
x^3-y^3=(x-y)(x^2+y^2+xy)
x^3-y^3=(x-y)(0)
x^3-y^3=0
the answer to the third question is:-
25x^2-1+1+5x^2
25x^2+5x^2
30x^2
3x(10x)
therefore =d)

Answer 2

according to me the answer to the first one should be d)
the answer to the second one is:-
x/y+y/x=-1
x^2+y^2=-x*y
x^3-y^3=(x-y)(x^2+y^2+xy)
x^3-y^3=(x-y)(0)
x^3-y^3=0
the answer to the third question is:-
25x^2-1+1+5x^2
25x^2+5x^2
30x^2
3x(10x)