Mobile Apps Development 2000 Words Paper
carolsimon
Trigonometry Exam 4 (Due Friday, 10/21, by 9:05 am) Fall 2016
Name:
You must show ALL work to receive full credit. Please name/list the trig identity used, when appropriate.
1. Verify the identity.
2 − 𝑠𝑖𝑛2𝜃
𝑐𝑜𝑠𝜃 = 𝑠𝑒𝑐𝜃 + 𝑐𝑜𝑠𝜃
2. Use the appropriate identity to find the EXACT VALUE.
tan 10°+tan 35°
1−tan 10° tan 35°
Trigonometry Exam 4 (Due Friday, 10/21, by 9:05 am) Fall 2016
3. Find cos(𝑥 + 𝑦) if tan 𝑥 = 2 3⁄ , tan 𝑦 = 1
3⁄ , 𝑥 is in quadrant I, and 𝑦 is in quadrant III.
4. Verify the identity.
tan 𝑥 − tan 𝑦 = sin(𝑥 − 𝑦)
cos 𝑥 cos 𝑦
Trigonometry Exam 4 (Due Friday, 10/21, by 9:05 am) Fall 2016
5. Use the given information and the appropriate indentity to find the exact value of sin 2𝑥,
cos 2𝑥, 𝑎𝑛𝑑 tan 2𝑥. [Hint: Draw a reference triangle.]
cos 𝑥 = − 8
17 , 𝜋 2⁄ < 𝑥 < 𝜋
6. Use the half-angle identities to find the EXACT VALUE.
tan 75°
Trigonometry Exam 4 (Due Friday, 10/21, by 9:05 am) Fall 2016
7. Verify the identity.
sin 2𝑥 = 2 tan 𝑥
1 + 𝑡𝑎𝑛2𝑥
8. Evaluate exactly using an appropriate identity.
cos 285° + cos 195°
9. Verify the identity.
sin 𝑥 − sin 𝑦
cos 𝑥 − cos 𝑦 = − cot (
𝑥 + 𝑦
2 )