Trigonometry Examples

$\sin (x) \cos (2 x)$

Step 1

Use the double-angle identity to transform $\cos (2 x)$ to $2 \cos^{2} (x) - 1$ .

$\sin (x) (2 \cos^{2} (x) - 1)$

Step 2

Simplify by multiplying through.

Tap for more steps...

Step 2.1

Apply the distributive property.

$\sin (x) (2 \cos^{2} (x)) + \sin (x) \cdot - 1$

Step 2.2

Reorder.

Tap for more steps...

Step 2.2.1

Rewrite using the commutative property of multiplication.

$2 \sin (x) \cos^{2} (x) + \sin (x) \cdot - 1$

Step 2.2.2

Move $- 1$ to the left of $\sin (x)$ .

$2 \sin (x) \cos^{2} (x) - 1 \cdot \sin (x)$

Step 3

Rewrite $- 1 \sin (x)$ as $- \sin (x)$ .

$2 \sin (x) \cos^{2} (x) - \sin (x)$