Math Core

Unit 7 · Test

Unit 7 test: Trigonometric Equations

14 questions. Answer them all, then submit to see your score. Solutions unlock after you submit.

This test covers solving basic trig equations, equations with multiple and shifted angles, and equations that need identities. Unless a problem says otherwise, give exact answers on [0,2π)[0, 2\pi).

Question 1

Solve 2sin⁡x+3=02\sin x + \sqrt{3} = 0 on [0,2π)[0, 2\pi).

Separate answers with commas, e.g. 2, -5

Question 2

Solve tan⁡θ=−1\tan\theta = -1 on [0∘,360∘)[0^\circ, 360^\circ). Give your answers in degrees.

Separate answers with commas, e.g. 2, -5

Question 3

Solve cos⁡θ=0.6\cos\theta = 0.6 on [0∘,360∘)[0^\circ, 360^\circ). Round each answer to the nearest tenth of a degree.

Separate answers with commas, e.g. 2, -5

Question 4

Which equation has no solution?

Question 5

Which is the general solution of 2cos⁡x=32\cos x = \sqrt{3}? (kk is any integer.)

Question 6

Solve 2sin⁡2x−sin⁡x=02\sin^2 x - \sin x = 0 on [0,2π)[0, 2\pi).

Separate answers with commas, e.g. 2, -5

Question 7

Solve sin⁡2x=−1\sin 2x = -1 on [0,2π)[0, 2\pi).

Separate answers with commas, e.g. 2, -5

Question 8

Solve cos⁡3θ=0\cos 3\theta = 0 on [0∘,360∘)[0^\circ, 360^\circ). Give your answers in degrees.

Separate answers with commas, e.g. 2, -5

Question 9

How many solutions does tan⁡3x=2\tan 3x = 2 have on [0,2π)[0, 2\pi)?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 10

Solve 2cos⁡(x−π4)=22\cos\left(x - \dfrac{\pi}{4}\right) = \sqrt{2} on [0,2π)[0, 2\pi).

Separate answers with commas, e.g. 2, -5

Question 11

The depth of water at a dock is d(t)=6+2sin⁡(πt6)d(t) = 6 + 2\sin\left(\dfrac{\pi t}{6}\right) feet, tt hours after midnight. For 0≤t<120 \le t < 12, at what times is the water 77 feet deep? Give the values of tt.

Separate answers with commas, e.g. 2, -5

Question 12

Solve 2cos⁡2x+3sin⁡x−3=02\cos^2 x + 3\sin x - 3 = 0 on [0,2π)[0, 2\pi).

Separate answers with commas, e.g. 2, -5

Question 13

Solve cos⁡2x+cos⁡x+1=0\cos 2x + \cos x + 1 = 0 on [0,2π)[0, 2\pi).

Separate answers with commas, e.g. 2, -5

Question 14

Solve sin⁡x+cos⁡x=−1\sin x + \cos x = -1 on [0,2π)[0, 2\pi). (If you square both sides, check every answer.)

Separate answers with commas, e.g. 2, -5