Ответ(ы) на вопрос:
[latex] \frac{10sin40sin50}{cos10} = \frac{10(cos(40-50)-cos(40+50))}{2cos10} = \\\ =\frac{5(cos(-10)-cos90)}{cos10} =\frac{5(cos10-0)}{cos10} =\frac{5cos10}{cos10} =5[/latex]
[latex] \frac{10sin40*sin50}{cos10}= \frac{10sin40*sin(90-40)}{cos10}= \frac{10sin40*cos40}{cos10}= [/latex]
[latex]= \frac{5sin80}{cos10}= \frac{5sin(90-10)}{cos10}= \frac{5cos10}{cos10}=5 [/latex]
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