# Assessment for Identities

## Objective

SWBAT use identities to verify other identities and evaluate trigonometric functions

#### Big Idea

Through a written assessment students demonstrate their proficiency in using trigonometric identities to verify identities and evaluate trigonometric functions.

## Assessment

45 minutes

For this assessment students are allowed to use the reference sheet they developed during the unit. The one shared was typed by a students and shared with anyone that wished to have the sheet.

I allow the use of the identity sheet because the main goal of this unit is for students to use the identities.  I also teach calculus and I find that the students know the important identities even though I do not have them memorize them for this test.

On this test, I do allow students to get a hint on the first 2 questions if they get stuck.  I will deduct points by determining how much of a hint the student needed.  Correcting a sign error is not as much of an error as reminding students of the property needed to start the problem.

Question 3 on the test allows students to show their reasoning.  I did not state which formula to use so the students can solve it many different ways.

Students sometimes struggle with question 4.  I made cos B=-3/4 to make sure students realize that just because you see a 3 and a 4 the other side (y in this case) is not necessarily 5.  That is a common error.  The other error is simplifying with radicals. Some students are not sure how to write (3)(-sqrt21). We have briefly reviewed this in class but many panic on tests and forget what happened on homework.

On the last 2 problems students struggle with computations with fractions. This is an issue I work on throughout the course.  I try to work with students on an individual basis to fix the errors or misconceptions.