Which of the following describes all values of x for which 1-x2≥0?

Which of the following describes all values of x for which 1-x²≥0?

A x≥1

B x≤-1

C 0≤x≤1

D x≤-1 or x≥1

Correct Answer: Option E

1-x^2 >= 0

---> x^2-1<=0

--> (x+1)(x-1)<=0

Above equation true for

i) x+1<=0 and x-1>=0

---> x<= -1 and x>=1

---> this is not possible ---Strike out this solution

ii) x+1>=0 and x-1<=0

---> x>=-1 and x<=1

--> -1<=x<=1