Mathematics for IGCSE & O level - Indices 2 (Section 3 - No. 15)
Which expressions are equivalent to ( rac{1}{9} )? (Select all that apply)
(3^{-2})
(9^{-1})
(-3^2)
(3^2)
解释
The reciprocal of (3^2) (which is 9) is ( rac{1}{9}), therefore, (3^{-2}) and (9^{-1}) are equivalent. (-3^2) and (3^2) are incorrect.