Categories
Feedback Trig Identities Trigonometric Functions

Trig Identities are just really hard to prove

photo (5)

 

What’s going on here? Tell a story of how this kid wrote this stuff?

Thanks to Jonathan Newman for the submission!

Categories
Distance Between Points Geometry Trigonometric Functions Trigonometry

Estimating cosine ( + Distance Bonus Mistake! )

IMG_2656

 

What does this response reveal about this student’s understanding of the basic trig functions?

(Bonus! What’s up with that response for distance? Can you explain why that mistake is a tempting one to make?)

 

 

Categories
Feedback Law of Sines Trigonometric Functions

Interesting Triangle

InterestingTriangle

Gregory Taylor sends this along, and asks a really great question about the work:

“Look past the problem of the original triangle having no 90 degrees… they know enough to run a (problematic) check on height to investigate ambiguity of sine.  Why would they even do that if they thought it was a right triangle?”

Any answers?

 

Categories
Trig Identities Trigonometric Functions

You ready for some more trig identities?

precalc 24

 

Thanks to Tina Cardone for her pile of trig submissions.

How would you help this student?

Categories
Graphing Trig Functions Trigonometric Functions

Amplitude and Period

precalc 15

 

What does this student know? How would you take the kid to the next level?

Thanks to the Ultimate Tina Cardone for her excellent submissions. Her reign of terror over this blog will end soon!

Categories
Law of Sines Trigonometric Functions

Law of Sines

precalc 8

 

Courtesy of Tina Cardone and presented without comment.

Categories
Exact Values of Trig Functions Trigonometric Functions

sin(75) = …

precalc 21 2 precalc 21 3 precalc 21

 

What do these responses reveal about what the students know about trig? Or just comment about what you find interesting here.

Thanks to the Incredible Tina Cardone for the submissions.

Categories
Equations of Parallel and Perpendicular Lines Linear, Quadratic, and Exponential Models* slope

Holy cow, there’s a lot to dig into here. Read this post carefully.

geom26 question

 

geom 26 4 geom 26 geom 26 3 (640x422) geom 26 2 (742x800)

 

There’s a ton to comment on here. I doubt you’ll need much in the way of a prompt, but here goes: what mistakes are missing? You grade this test on Sunday; what does Monday’s class look like?

Thanks to Tina Cardone, who is not-so-slowly taking over this blog, for the submission.

Categories
Trig Identities Trigonometric Functions

QED?

jnewman2

 

What’s the fastest way to help this student?

Do you have a good way to help students understand the rigor needed in these sort of proofs?

Thanks to Jonathan Newman for the submission.

Categories
Trig Identities Trigonometric Functions

A Sneaky Simplifying Mistake

jnewman1

 

This is a fun mistake, via Jonathan Newman. Find it, and then explain how you’d help the kid who made it.