Trig equation quadratic in sin or cos: solve or count solutions

1. A.
   $n\pi + (-1)^n\frac{\pi}{3},\; n\in\mathbb{Z}$
2. B.
   $n\pi + (-1)^n\frac{\pi}{6},\; n\in\mathbb{Z}$
3. C.
   $n\pi \pm (-1)^n\frac{\pi}{4},\; n\in\mathbb{Z}$
4. D.
   $n\pi + (-1)^n\frac{2\pi}{3},\; n\in\mathbb{Z}$

Tap an option to check your answer.

1. A.
   $\left\{\frac{\pi}{6}, \frac{5\pi}{6}\right\}$
2. B.
   $\left\{\frac{\pi}{3}, \frac{5\pi}{3}\right\}$
3. C.
   $\left\{\frac{\pi}{3}, \frac{2\pi}{3}\right\}$
4. D.
   $\left\{\frac{2\pi}{3}, \frac{4\pi}{3}\right\}$

Tap an option to check your answer.

1. A.
   0
2. B.
   5
3. C.
   6
4. D.
   10

Tap an option to check your answer.

1. A.
   7
2. B.
   6
3. C.
   1
4. D.
   7

Tap an option to check your answer.

1. A.
   $\left\{\frac{\pi}{3},\frac{2\pi}{3}\right\}$
2. B.
   $\left\{\frac{\pi}{3},\frac{4\pi}{3}\right\}$
3. C.
   $\left\{\frac{2\pi}{3},\frac{4\pi}{3}\right\}$
4. D.
   $\left\{\frac{2\pi}{3},\frac{5\pi}{3}\right\}$

Tap an option to check your answer.

1. A.
   6
2. B.
   1
3. C.
   2
4. D.
   4

Tap an option to check your answer.

1. A.
   $8x^2 - 6\pi x + \pi^2 = 0$
2. B.
   $4x^2 - 6\pi x + \pi^2 = 0$
3. C.
   $8x^2 + 6\pi x + \pi^2 = 0$
4. D.
   $4x^2 + 6\pi x + \pi^2 = 0$

Tap an option to check your answer.