Question

Sin30⁰•cos60⁰-cos²120⁰+sin135⁰•cos90⁰;​

Answer 1

Ответ:

0.

Объяснение:

sin30⁰•cos60⁰-cos²120⁰+sin135⁰•cos90⁰ = 1/2•1/2 - cos²(180⁰-60°) + sin135°•cos90⁰; = 1/4 - cos²60° + sin135°•0 = 1/4 - (1/2)² + 0 = 1/4 - 1/4 = 0.

Answer 2

To evaluate the given expression, let's calculate each term step by step:

1. sin(30°) • cos(60°): sin(30°) = 0.5 cos(60°) = 0.5 0.5 • 0.5 = 0.25

2. cos²(120°): cos(120°) = -0.5 cos²(120°) = (-0.5)² = 0.25

3. sin(135°) • cos(90°): sin(135°) = √2 / 2 ≈ 0.7071 cos(90°) = 0 0.7071 • 0 = 0

Now, substituting these values into the expression: 0.25 - 0.25 + 0 = 0

Therefore, the value of the given expression is 0.