10 a Use a calculator to find1.1 Irrational numbersi (2+1)×(2−1)ii (3+1)×(3−1)b Continue the pattern of the multiplications in part a.iii (4+1)×(4−1)c Generalise the results to find (N+1)×(N−1) where N is a positive integer.d Check your generalisation with further examples.11 Here is a decimal: 5.020020002000020000 examples.
Q. 10 a Use a calculator to find1.1 Irrational numbersi (2+1)×(2−1)ii (3+1)×(3−1)b Continue the pattern of the multiplications in part a.iii (4+1)×(4−1)c Generalise the results to find (N+1)×(N−1) where N is a positive integer.d Check your generalisation with further examples.11 Here is a decimal: 5.020020002000020000 examples.
Calculate Formula: Calculate (2+1)×(2−1) Use the difference of squares formula: (a+b)(a−b)=a2−b2 Here, a=2 and b=1. (2+1)×(2−1)=(2)2−(1)2=2−1=1
Use Difference of Squares: Calculate (3+1)×(3−1)Again, use the difference of squares formula: (a+b)(a−b)=a2−b2Here, a=3 and b=1.(3+1)×(3−1)=(3)2−(1)2=3−1=2
Calculate Result: Calculate (4+1)×(4−1) Use the difference of squares formula: (a+b)(a−b)=a2−b2 Here, a=4 and b=1. (4+1)×(4−1)=(4)2−(1)2=4−1=3
Generalize for N: Generalize the result for (N+1)×(N−1) Using the pattern from the previous steps, we can generalize: (\sqrt{N}+\(1)\times(\sqrt{N}−1) = (\sqrt{N})^2 - (1)^2 = N - 1
Check with Examples: Check the generalization with further examplesLet's check with N=5 and N=6:For N=5:(5+1)×(5−1)=(5)2−(1)2=5−1=4For N=6:(6+1)×(6−1)=(6)2−(1)2=6−1=5Both results match the generalization.