Question

2sin^2 20°+2cos^2 20°-cos^2 30°​

Answer 1

Ответ:1+Sin² 30°

Объяснение    

2sin² 20°+2cos² 20°-cos² 30°​=(2sin² 20°+2cos² 20)°-cos² 30°​= 2(sin² 20°+cos² 20)°-cos² 30°​= 2·1-cos² 30°=2-cos² 30°= 1+(1-cos² 30°)= 1+Sin² 30°

Answer 2

Надеюсь помогла) удачи)

Answer 3

To simplify the expression 2sin^2(20°) + 2cos^2(20°) - cos^2(30°), you can use trigonometric identities.

1. Start by using the trigonometric identity sin^2(θ) + cos^2(θ) = 1 for any angle θ.

2. Then, sin^2(θ) = 1 - cos^2(θ), so you can rewrite sin^2(20°) as 1 - cos^2(20°).

3. Now, your expression becomes:

2(1 - cos^2(20°)) + 2cos^2(20°) - cos^2(30°).

4. Distribute the 2 on the left side:

2 - 2cos^2(20°) + 2cos^2(20°) - cos^2(30°).

5. Notice that the 2cos^2(20°) and -2cos^2(20°) cancel each other out, leaving you with:

2 - cos^2(30°).

6. Finally, cos(30°) = √3/2, so:

2 - (3/4) = 8/4 - 3/4 = 5/4.

So, the simplified expression is 5/4.