sin(15)=0,258819
можно расписать как sin(60-45)= sin(60)*cos(45)-sin(45)*cos(60)=
<span>f′(x)=<span><span>(<span><span>sin<span>(x)</span>+cos<span>(x)/</span></span><span>sin<span>(x)</span>−cos<span>(x)</span></span></span>)</span>′</span>=</span><span><span>=<span><span><span><span>(<span>sin<span>(x)</span>+cos<span>(x)</span></span>)</span>′</span>⋅<span>(<span>sin<span>(x)</span>−cos<span>(x)</span></span>)</span>−<span>(<span>sin<span>(x)</span>+cos<span>(x)</span></span>)</span>⋅<span><span>(<span>sin<span>(x)</span>−cos<span>(x)</span></span>)</span>′/</span></span><span><span>(<span>sin<span>(x)</span>−cos<span>(x)</span></span>)^</span>2</span></span></span>=</span><span>=<span><span><span><span>(<span><span><span>(<span>sin<span>(x)</span></span>)</span>′</span>+<span><span>(<span>cos<span>(x)</span></span>)</span>′</span></span>)</span>⋅<span>(<span>sin<span>(x)</span>−cos<span>(x)</span></span>)</span>−<span>(<span>sin<span>(x)</span>+cos<span>(x)</span></span>)</span></span><span>⋅<span>(<span><span><span>(<span>sin<span>(x)</span></span>)</span>′</span>−<span><span>(<span>cos<span>(x)</span></span>)</span>′</span></span>)/</span></span></span><span><span>(<span>sin<span>(x)</span>−cos<span>(x)</span></span>)^</span>2</span></span>=</span><span>=<span><span><span><span>(<span>cos<span>(x)</span>+<span>(<span>−sin<span>(x)</span></span>)</span></span>)</span>⋅<span>(<span>sin<span>(x)</span>−cos<span>(x)</span></span>)</span>−<span>(<span>sin<span>(x)</span>+cos<span>(x)</span></span>)</span></span><span>⋅<span>(<span>cos<span>(x)</span>−<span>(<span>−sin<span>(x)</span></span>)</span></span>)/</span></span></span><span><span>(<span>sin<span>(x)</span>−cos<span>(x)</span></span>)^</span><span>2</span></span></span></span>
Задача 1
80 : 2/15 = ( 80 * 15 ) : 2 = 600 ( m^2 )
ОТВЕТ 600 m^2
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Задача 2
18 : 30 = 6/10 = 3/5 ( части )
или 0,6 части
ОТВЕТ 3/5 части
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задача 3
30 * 0,3 = 9 ( руб) стоит мороженое
ОТВЕТ 9 рублей
a и b - стороны квадратов
a² и b² - площади квадратов
Или a = 3 , а b = 4 . Или a = 4 , b = 3
Ответ : стороны квадратов 3 дм и 4 дм .
