4.2: Trig Proofs Difficulty Level: At Grade Created by: CK-12 Share Add to Library Turn In Read Resources Details This activity is intended to supplement Trigonometry, Chapter 3, Lesson 2. Problem 1 – Using the Calculator for verification 1. Prove: (1+cosx)(1−cosx)=sin2x. Verify the proof graphically. Enter the left side of the equation in Y1 and the right side of the equation in Y2. Problem 2 - Confirm your findings For questions 2 through 5, prove the equation given and then verify it graphically. For cotx, type (1tanx). For secx, type (1cosx). 2. sinx⋅cotx⋅secx=1 3. sec2x−1sec2x=sin2x 4. tanx+cotx=secx(cscx) 5. sin2x−49sin2x+14sinx+49=sinx−7sinx+7 Notes/Highlights Having trouble? Report an issue. Color Highlighted Text Notes Please Sign In to create your own Highlights / Notes Show More Image Attributions Show Hide Details Description No description available here... Tags: angle sum and difference proofs Pythagorean theorem (4 more) TI.MAT.ENG.SE.1.Trigonometry.4 trigonometric identities unit circle verifying identities Subjects: mathematics Grades: 11 , 12 Date Created: Feb 23, 2012 Last Modified: Nov 04, 2014 Save or share your relevant files like activites, homework and worksheet.To add resources, you must be the owner of the section. Click Customize to make your own copy.