Question

(Cos105-cos75)×cos15

Answer 1

Ответ: -1/2

Пошаговое объяснение:

=(cos(90+15)-cos(90-15))*cos15=( -sin15-sin15)*cos15= -2sin15*cos15=

-sin30=-1/2

Answer 2

Let's break down the expression step by step:

1. Calculate the values of cos(105°) and cos(75°):

cos(105°) ≈ -0.258819 cos(75°) ≈ 0.258819

2. Calculate the value of cos(15°):

cos(15°) ≈ 0.965926

3. Now, substitute the values back into the expression:

(Cos105 - Cos75) × Cos15 = (-0.258819 - 0.258819) × 0.965926 ≈ -0.517638 × 0.965926 ≈ -0.499999

So, (Cos105 - Cos75) × Cos15 is approximately -0.5.