u/Haunting-Implement-4

Hi guys, I'm in northeastern MA. Curious if this is yellow nutsedge. I just put down the Roundup spray that is safe for lawns, and it advertises that it kills dandelions, yellow nutsedge, etc. And it did take care of many other weeds, but this looks like it's staying strong. It grows much faster and taller than the regular grass.

If it is in fact yellow nutsedge, can you recommend a product to get rid of it?

Thank you.