Ask
your own question, for FREE!
Mathematics
13 Online
OpenStudy (anonymous):
calculate
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
\[3^{64}\mod 67\]
OpenStudy (anonymous):
by repeated squaring or fermat theorem or otherwise
OpenStudy (amistre64):
3^4 = 81 = 14 mod 67
OpenStudy (amistre64):
(14*14) = 62 mod 67
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (amistre64):
or -5 mod 67 might be simpler to work with
OpenStudy (anonymous):
can this simplify to a number
OpenStudy (amistre64):
it eventually goes to 15 i believe
OpenStudy (anonymous):
from
3^64 mod 67
3433683820292512484657849089281 mod 67
I got 15? Check with everyone else...
OpenStudy (anonymous):
ye,15 is correct
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
Great! You got it then
OpenStudy (amistre64):
3^(64) mod 67
(3^4)^16 mod 67
(14)^16 mod 67
(14^2)^8 mod 67
(-5)^8 mod 67
(25)^4 mod 67
(22)^2 mod 67
15 mod 67
OpenStudy (anonymous):
15 mod 67 = 15
OpenStudy (anonymous):
can we use fermat little theorem
\[a^{p-1}\equiv 1\mod p\]
OpenStudy (amistre64):
64 = 66-2 so maybe
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
\[3^{66}\equiv 1\mod 67\]
\[3^23^{64}\equiv 1\mod 67\]
OpenStudy (anonymous):
so we just need to invert 9 mod 67. You can either do this by the Euclidean algorithm, or
by inspection. For example, 67 ยท 2 + 1 = 135 = 15*9
OpenStudy (anonymous):
wat is the \[9^{-1}\equiv 15\mod 67\]
Can't find your answer?
Make a FREE account and ask your own questions, OR help others and earn volunteer hours!
Join our real-time social learning platform and learn together with your friends!