MA106ZN PreCalculus Trigonometry Test Review for Final Exam

MA-106-ZN, Pre-Calculus Trigonometry Test: Review for Final Exam (Practice Test) This Question: 1 pt 21 of 89(69 complete) Find the exact value of the expression. Do not use a calculator sin (-9x)+ cos (4x) Select the correct cho ce below and if necessary fil in the answer bo O A. sin(-9x)+ cos (4x)- to complete your choce. (Simplity your answer, including any radicals. Use integers or fractions for any numbers in the expression ) B. The answer is undefined se Click to select and enter your answer(s) O Type here to search 0 ip

Solution

We have

sin(-x) = sin(x)

Therefore sin(-9) = sin(9)

We have sin(9) = 0

cos(4) = 1

Therefore sin(-9) + cos(4) = 0+1

= 1