Спасайте, нужно решение

Question

Спасайте, нужно решение

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Answer 1

Cos(4x/3-3π/4)=√2/2
4x/3-3π/4=π/4+2πn U 4x/3-3π/4=-π/4+2πn
4x/3=3π/4+π/4+2πn U 4x/3=3π/4-π/4+2πn
4x/3=π+2πn U 4x/3=π/2+2πn
x=3π/4+3πn/2 U x=π/8+3πn/2
x={-3π/4;3π/4;-11π/8;π/8;13π/8}∈[-2π;2π]