Заранее
D=b^2-4ac
X=(-b+-кореньD)/2a
Общий вид уравнения касательной:
.
Найдем значение функции в точке
, получим
![f(1)=3-\sqrt{1}-\frac{2}{\pi}\sin\pi =3-1-0=2](https://tex.z-dn.net/?f=f%281%29%3D3-%5Csqrt%7B1%7D-%5Cfrac%7B2%7D%7B%5Cpi%7D%5Csin%5Cpi%20%3D3-1-0%3D2)
Найдем производную функции
![f'(x)=(3-\sqrt{x}-\frac{2}{\pi}\sin \pi x)=(3)'-(\sqrt{x})'-\frac{2}{\pi}\cdot(\sin\pi x)'=\\ \\ =-\frac{1}{2\sqrt{x}}-\frac{2}{\pi}\cdot \cos\pi x\cdot(\pi x)'=-\frac{1}{2\sqrt{x}}-\frac{2}{\pi}\cdot \cos\pi x\cdot \pi =-\frac{1}{2\sqrt{x}}-2\cos\pi x](https://tex.z-dn.net/?f=f%27%28x%29%3D%283-%5Csqrt%7Bx%7D-%5Cfrac%7B2%7D%7B%5Cpi%7D%5Csin%20%5Cpi%20x%29%3D%283%29%27-%28%5Csqrt%7Bx%7D%29%27-%5Cfrac%7B2%7D%7B%5Cpi%7D%5Ccdot%28%5Csin%5Cpi%20x%29%27%3D%5C%5C%20%5C%5C%20%3D-%5Cfrac%7B1%7D%7B2%5Csqrt%7Bx%7D%7D-%5Cfrac%7B2%7D%7B%5Cpi%7D%5Ccdot%20%5Ccos%5Cpi%20x%5Ccdot%28%5Cpi%20x%29%27%3D-%5Cfrac%7B1%7D%7B2%5Csqrt%7Bx%7D%7D-%5Cfrac%7B2%7D%7B%5Cpi%7D%5Ccdot%20%5Ccos%5Cpi%20x%5Ccdot%20%5Cpi%20%3D-%5Cfrac%7B1%7D%7B2%5Csqrt%7Bx%7D%7D-2%5Ccos%5Cpi%20x)
Значение производной функции в точке ![x_0=1](https://tex.z-dn.net/?f=x_0%3D1)
![f'(1)=-\frac{1}{2\cdot \sqrt{1}}-2\cos\pi=-0.5-2\cdot(-1)=-0.5+2=1.5](https://tex.z-dn.net/?f=f%27%281%29%3D-%5Cfrac%7B1%7D%7B2%5Ccdot%20%5Csqrt%7B1%7D%7D-2%5Ccos%5Cpi%3D-0.5-2%5Ccdot%28-1%29%3D-0.5%2B2%3D1.5)
Уравнение касательной:
![y=1.5(x-1)+2=1.5x-1.5+2=\boxed{1.5x+0.5}](https://tex.z-dn.net/?f=y%3D1.5%28x-1%29%2B2%3D1.5x-1.5%2B2%3D%5Cboxed%7B1.5x%2B0.5%7D)
Вычислить приближённое значение:
509.117
3) 27a³-8b³=(3a)³-(2b)³=(3a-2b)((3a)²+3a×2b+(2b)²)=(3a-2b)(9a²+6ab+4b²)
4) 1+64y³=(1+4y)(1-4y+16y²)
6) 1-8b³=(1-2b)(1+2b+4b²)
8)m³/64+n³/125=(m/4+n/5)(m²/16-mn/20+n²/25)
Решение
<span>7^2х+9 = 7^х-11
</span><span>7^2х - 7^х + 9 + 11 = 0
</span><span>7^2х - 7^х + 20 = 0
</span>7^x = t
t² - t + 20 = 0
D = 1 - 4*1*20 = - 79 < 0
решений нет