Question
If a = (√2 - 1)1/3, then the value of
(a-1/a)3 +3(a-1/a) is:Solution
a = (√2 - 1)1/3             both sides cube a3= (√2 - 1)    … (1) Now- (a-1/a)3 + 3(a-1/a)      using formula (a-b)3 =a3-b3-3ab(a-b) =a3-1/a3 -3×a×1/a(a-1/a) +3(a-1/a) = a3-1/a3 -3(a-1/a) + 3(a-1/a) = a3-1/a3 Now put the value of a3. = (√2 - 1) -1/ (√2 - 1) = (√2 - 1) – [(√2 + 1)/ (√2 - 1) (√2 + 1)] = (√2 - 1- √2 - 1) =-1-1 =-2.
- What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)
√323.89  × (3.20) ÷ 9.02 =?
24.11% of 249.99 + √143.97 ÷ 12.02 = ?
 5983.987 + 59832.999 – 598.873 = ?
(100.01% of 44.89) ÷ 14.98 = √? - √48.98
(5.013 – 30.04) = ? + 11.98% of 4799.98
(4096)1/3 × 10.11 × 11.97 ÷ 24.32 = ? + 15.022
- √81.45 + √225.60 + 49.89% of (520.43 + 22.13% of 131.45) = ?
40.024 of 54.89% of 19.9 = ? × √(2661.98/22.09)Â
Find the approximate value of Question mark(?) for given equation.Â
135.86% of 249.99 + 24.95 × 14.03 ÷ 2.01 = ?
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