Manhattan’s famed LaGuardia High School failed to craft a valid Advanced Placement Calculus class for students this year — leaving parents furious, the Post has learned.

In a letter to families this week, assistant principal Alyssa Collins said that the College Board deemed the school’s ongoing AP Calculus course ineligible for the designation.

The news comes just one year after the performing arts school sought to narrow its AP offerings but was forced to relent after a parental outcry.

“Here we are, one year later, and the AP Calculus class gets rejected,” one angry parent told The Post. “It’s hard not to read between the lines about what’s going on here.”

Collins told parents that the course will instead be called “Advanced Calculus” in student transcripts.

“Though this may sound significant, I would like to assure you that this decision by College Board, a private company, has no bearing on the learning experience for your child at LaGuardia,” she wrote. “The material and quality of work with which students engage on a daily basis will continue.”

Principal Yeou-Jey Vasconcelos tangled with parents last year after she proposed cutting back on AP classes to reduce stress on students and to give teachers more freedom in creating their curriculum.

But a PowerPoint presentation on the school’s AP courses last year offered an additional critique of the model.

LaGuardia — which counts Robert DeNiro and Liza Minnelli as graduates — told families that “colleges acknowledge that standardized test scores reflect systemic racism rather than student achievement,” according to the document.

School sources said that some AP teachers have been told to discourage kids from taking the exams, which confer college credits if students pass a corresponding test.

“While students were never required and are still not required to take the AP exam as part of taking this course, those students who choose to do so will still have the opportunity to take the exam,” Collins wrote to parents this week.

Critics noted that news of the College Board’s invalidation comes just two months before the scheduled test.

Others were concerned about student preparedness for the exam given the course’s failure to qualify as AP-appropriate.

“Per the terms of college applications, we will notify all colleges to which a student is applying of the course name change,” Collins wrote. “In our communication to colleges, we will share that though the course name has changed, the content and syllabus have not changed.”

Vasconcelos replaced former LaGuardia chief Lisa Mars in 2019 after some school factions found her to be too focused on academics.