Question

$1 - \cos(x) = 2 \sin( \frac{x}{2} )$
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Answer 1

Ответ:

1)  cos^2x = 1/2

cosx = - √2/2

x1 = (+ -)arccos(-√2/2) + 2πn, n∈Z

x1 = (+ -)(π - π/4) + 2πn, n∈z

x1 = (+ -)(3π/4) + 2πn, n∈Z

2)  cosx = √2/2

x2 = (+ -)arccos(√2/2) + 2πk, n∈Z

x2 = (+ -)(π/4) + 2πk, n∈Z

2)  sin^2x = 1

 a)  sinx = -1

 x1 = - π/2 + 2πm, m∈Z

b)  sinx = 1

x2 = π/2 + 2πk, k∈Z

Объяснение: