7÷0.7-7÷(8×0.7)= 7÷7/10 - 7÷(8×7/10)= 10- 7÷28/5= 10- 5/4=10 - 1.25 =8.75
Ответ:
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Sin(2x)-√(sinx*cosx)=0 ОДЗ: |x|≤1
2*sinx*cosx-√(sinx*cosx)=0
√(sinx*cosx)*(2*√(sinx*cosx)-1)=0
(√(sinx*cosx))²=0²
sinx*cosx=0
sinx=0 x₁=πn
cosx=0 x₂=π/2+πn
2*√(sinx*cosx)-1=0
(2*√(sinx*cosx))²=1²
4*(sinx*cosx)=1
2*sin(2x)=1 |÷2
sin(2x)=1/2
2x=π/6+2πn x₃=π/12+πn
2x=5π/6+2πт x₄=5π/12+πn.
Ответ: x₁=πn x₂=π/2+πn x₃=π/12+πn x₄=5π/12+πn.