√25х49=√1225=35
_√27,04_ = _5,2_
√90000 300
Ответ:
Объяснение:
(4a+5)/(a-4) - (a+17)/(a-4)= (4a+5-a-17)/(a-4)= (3a-12)/(a-4) =
=3(a-4)/(a-4)= 3
<em><u>Нужна помощь! Срочно!</u></em>
Вычислите:<em />
1) cos60*-√6cos30*sin45*+ctg30*tg150*-tg45*
2) sin pi/6 + √2cos 3pi/4 -√3ctg pi/3
![1)f(x)=3x-\frac{1}{3}x^{3}-x^{2}\\\\f'(x)=3(x)'-\frac{1}{3}(x^{3})'-(x^{2})'=3-\frac{1}{3}*3x^{2}-2x=3-x^{2}-2x\\\\f'(x)<0\Rightarrow -x^{2}-2x+3<0\\\\x^{2}+2x-3>0\\\\(x-1)(x+3)>0](https://tex.z-dn.net/?f=1%29f%28x%29%3D3x-%5Cfrac%7B1%7D%7B3%7Dx%5E%7B3%7D-x%5E%7B2%7D%5C%5C%5C%5Cf%27%28x%29%3D3%28x%29%27-%5Cfrac%7B1%7D%7B3%7D%28x%5E%7B3%7D%29%27-%28x%5E%7B2%7D%29%27%3D3-%5Cfrac%7B1%7D%7B3%7D%2A3x%5E%7B2%7D-2x%3D3-x%5E%7B2%7D-2x%5C%5C%5C%5Cf%27%28x%29%3C0%5CRightarrow%20-x%5E%7B2%7D-2x%2B3%3C0%5C%5C%5C%5Cx%5E%7B2%7D%2B2x-3%3E0%5C%5C%5C%5C%28x-1%29%28x%2B3%29%3E0)
+ - +
________₀_________₀_________
- 3 1
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Ответ : x ∈ (- ∞ ; - 3) ∪ (1 ; + ∞)
![2)f(x)=\frac{2x}{(x-1)^{2} }\\\\f'(x)=\frac{2(x)'*(x-1)^{2}-2x*((x-1)^{2})'}{(x-1)^{4}}=\frac{2*(x^{2}-2x+1)-2x*2(x-1)}{(x-1)^{4}}=\frac{2x^{2}-4x+2-4x^{2}+4x}{(x-1)^{4}}=\frac{-2x^{2}+2 }{(x-1)^{4}}=\frac{-2(x^{2}-1)}{(x-1)x^{4}}\\\\f'(x)=0\Rightarrow\\\\\left \{ {{x^{2}-1=0 } \atop {x-1\neq0 }} \right. \\\\\\\left \{ {{(x-1)(x+1)=0} \atop {x\neq1 }} \right. \\\\\\\left \{ {{\left[\begin{array}{ccc}x_{1}=-1 \\x_{2} =1-neyd\end{array}\right } \atop {x\neq1 }} \right. \\\\](https://tex.z-dn.net/?f=2%29f%28x%29%3D%5Cfrac%7B2x%7D%7B%28x-1%29%5E%7B2%7D%20%7D%5C%5C%5C%5Cf%27%28x%29%3D%5Cfrac%7B2%28x%29%27%2A%28x-1%29%5E%7B2%7D-2x%2A%28%28x-1%29%5E%7B2%7D%29%27%7D%7B%28x-1%29%5E%7B4%7D%7D%3D%5Cfrac%7B2%2A%28x%5E%7B2%7D-2x%2B1%29-2x%2A2%28x-1%29%7D%7B%28x-1%29%5E%7B4%7D%7D%3D%5Cfrac%7B2x%5E%7B2%7D-4x%2B2-4x%5E%7B2%7D%2B4x%7D%7B%28x-1%29%5E%7B4%7D%7D%3D%5Cfrac%7B-2x%5E%7B2%7D%2B2%20%7D%7B%28x-1%29%5E%7B4%7D%7D%3D%5Cfrac%7B-2%28x%5E%7B2%7D-1%29%7D%7B%28x-1%29x%5E%7B4%7D%7D%5C%5C%5C%5Cf%27%28x%29%3D0%5CRightarrow%5C%5C%5C%5C%5Cleft%20%5C%7B%20%7B%7Bx%5E%7B2%7D-1%3D0%20%7D%20%5Catop%20%7Bx-1%5Cneq0%20%7D%7D%20%5Cright.%20%5C%5C%5C%5C%5C%5C%5Cleft%20%5C%7B%20%7B%7B%28x-1%29%28x%2B1%29%3D0%7D%20%5Catop%20%7Bx%5Cneq1%20%7D%7D%20%5Cright.%20%5C%5C%5C%5C%5C%5C%5Cleft%20%5C%7B%20%7B%7B%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx_%7B1%7D%3D-1%20%5C%5Cx_%7B2%7D%20%3D1-neyd%5Cend%7Barray%7D%5Cright%20%7D%20%5Catop%20%7Bx%5Cneq1%20%7D%7D%20%5Cright.%20%5C%5C%5C%5C)
![Otvet:\boxed{-1}](https://tex.z-dn.net/?f=Otvet%3A%5Cboxed%7B-1%7D)
![3)f(x)=x*Cos2x\\\\f'(x)=(x)'*Cos2x+x*(Cos2x)'=1*Cos2x+x*(-2Sin2x)=Cos2x-2xSin2x\\\\f'(0)=Cos0-2*0*Sin0=1-0=1](https://tex.z-dn.net/?f=3%29f%28x%29%3Dx%2ACos2x%5C%5C%5C%5Cf%27%28x%29%3D%28x%29%27%2ACos2x%2Bx%2A%28Cos2x%29%27%3D1%2ACos2x%2Bx%2A%28-2Sin2x%29%3DCos2x-2xSin2x%5C%5C%5C%5Cf%27%280%29%3DCos0-2%2A0%2ASin0%3D1-0%3D1)