AP EAMCET201823 Apr 2018Evening ShiftMathematicsMathematical InductionActual
If 2 (4^ 2 n+1 )+3^ 3 n+1 is divisible by k, k>1 for all n N , then the value of k is
Options
- A19
- B17
- C11
- D13
Correct answer
C. 11
Step-by-step solution
The given expression aligned & 2 (4^ 2 n+1 )+3^ 3 n+1 =P(n) & P(n)=8 (4^ 2 n )+3 (3^ 3 n ) & For n=1 , & n N & P(n=1)=128+81=209 & aligned is divisible by 19 and 11. Similarly, P(n=2)=2048+2187=4235 is divisible by 11 but not divisible by 19. So, the given expression 2 (4^ 2 n+1 )+3^ 3 n+1 is divisible by For all k=11 n N .