John Rock
@johnrockmath.bsky.social
Professor at Cal Poly Pomona, mathematician | Free PDF of Arbitrarily Close: https://www.cpp.edu/faculty/jarock/arbitrarily-close.shtml | Print versions available from 619 Wreath: https://www.619wreath.com/acl.html
Arbitrarily Close: An Introduction to Real Analysis has been published by 619 Wreath! Free PDF, Desmos, and GeoGebra available on my faculty webpage (at least for the time being): www.cpp.edu/faculty/jaro...
Hardcover and paperback copies are available from 619 Wreath: www.619wreath.com/acl.html
Hardcover and paperback copies are available from 619 Wreath: www.619wreath.com/acl.html
October 25, 2025 at 7:45 PM
Arbitrarily Close: An Introduction to Real Analysis has been published by 619 Wreath! Free PDF, Desmos, and GeoGebra available on my faculty webpage (at least for the time being): www.cpp.edu/faculty/jaro...
Hardcover and paperback copies are available from 619 Wreath: www.619wreath.com/acl.html
Hardcover and paperback copies are available from 619 Wreath: www.619wreath.com/acl.html
Reposted by John Rock
I want to be romantic about baseball, but it broke my heart tonight instead
This was Vin Scully's call of Henry Aaron's 715th home run. Tonight Major League Baseball cut off the first sentence, starting it with the "What a marvelous moment" part because they don't want to anger the white supremacists who run our country and of whom Rob Manfred is an ardent supporter.
July 16, 2025 at 4:04 AM
I want to be romantic about baseball, but it broke my heart tonight instead
Reposted by John Rock
Hey remember when the one of the most prominent Democrats in Minnesota and her husband were assassinated
June 22, 2025 at 3:38 AM
Hey remember when the one of the most prominent Democrats in Minnesota and her husband were assassinated
Reposted by John Rock
If you do the alternating sum of the digits of a whole number, you can tell if that number is divisible by 11. Here's how and why it works:
May 28, 2025 at 1:28 AM
If you do the alternating sum of the digits of a whole number, you can tell if that number is divisible by 11. Here's how and why it works:
Reposted by John Rock
Walz: If you say you love freedom but you don't believe freedom is for everybody, then the thing you love is not freedom, it is privilege.
April 24, 2025 at 12:23 AM
Walz: If you say you love freedom but you don't believe freedom is for everybody, then the thing you love is not freedom, it is privilege.
Reposted by John Rock
I see it. I have lived it. 83 years ago, the U.S. government turned upon a group of its own citizens and residents and sent them to internment camps without due process. I was there among them. American fascism is back. It is here. It is now.
April 15, 2025 at 8:30 PM
I see it. I have lived it. 83 years ago, the U.S. government turned upon a group of its own citizens and residents and sent them to internment camps without due process. I was there among them. American fascism is back. It is here. It is now.