Формула Тейлора в неё подставляют найденные значения по f(x)=2ˣ
![{\displaystyle \sum _{n=0}^{k}{\frac {f^{(n)}(a)}{n!}}(x-a)^{n}=f(a)+f'(a)(x-a)+{\frac {f^{(2)}(a)}{2!}}(x-a)^{2}+\ldots +{\frac {f^{(k)}(a)}{k!}}(x-a)^{k}};](https://tex.z-dn.net/?f=%7B%5Cdisplaystyle+%5Csum+_%7Bn%3D0%7D%5E%7Bk%7D%7B%5Cfrac+%7Bf%5E%7B%28n%29%7D%28a%29%7D%7Bn%21%7D%7D%28x-a%29%5E%7Bn%7D%3Df%28a%29%2Bf%27%28a%29%28x-a%29%2B%7B%5Cfrac+%7Bf%5E%7B%282%29%7D%28a%29%7D%7B2%21%7D%7D%28x-a%29%5E%7B2%7D%2B%5Cldots+%2B%7B%5Cfrac+%7Bf%5E%7B%28k%29%7D%28a%29%7D%7Bk%21%7D%7D%28x-a%29%5E%7Bk%7D%7D%3B)
f'''(x)=(2ˣln²2)'=ln²2(2ˣ)'=ln²2*2ˣ*ln2=2ˣln³2;
f'''(0)=2⁰ln³2=1*ln³2=ln³2;
f(n производных)(0)=lnⁿ2;
Подставляем значения в ряд Тейлора:
![\displaystyle \sum _{n=0}^{k}{\frac {f^{(n)}(a)}{n!}}(x-a)^{n}=f(0)+f'(0)(x-0)+{\frac {f^{(2)}(0)}{2!}}(x-0)^{2}+\ldots +{\frac {f^{(k)}(0)}{k!}}(x-0)^{k}}=\\f(0)+f'(0)x+{\frac {f^{(2)}(0)}{2!}}x^2+\ldots +{\frac {f^{(k)}(0)}{k!}}x^{k}}=\\1+xln2+{\frac {ln^2}{2}}x^2+\ldots +{\frac {ln^k2}{k!}}x^{k}};](https://tex.z-dn.net/?f=%5Cdisplaystyle+%5Csum+_%7Bn%3D0%7D%5E%7Bk%7D%7B%5Cfrac+%7Bf%5E%7B%28n%29%7D%28a%29%7D%7Bn%21%7D%7D%28x-a%29%5E%7Bn%7D%3Df%280%29%2Bf%27%280%29%28x-0%29%2B%7B%5Cfrac+%7Bf%5E%7B%282%29%7D%280%29%7D%7B2%21%7D%7D%28x-0%29%5E%7B2%7D%2B%5Cldots+%2B%7B%5Cfrac+%7Bf%5E%7B%28k%29%7D%280%29%7D%7Bk%21%7D%7D%28x-0%29%5E%7Bk%7D%7D%3D%5C%5Cf%280%29%2Bf%27%280%29x%2B%7B%5Cfrac+%7Bf%5E%7B%282%29%7D%280%29%7D%7B2%21%7D%7Dx%5E2%2B%5Cldots+%2B%7B%5Cfrac+%7Bf%5E%7B%28k%29%7D%280%29%7D%7Bk%21%7D%7Dx%5E%7Bk%7D%7D%3D%5C%5C1%2Bxln2%2B%7B%5Cfrac+%7Bln%5E2%7D%7B2%7D%7Dx%5E2%2B%5Cldots+%2B%7B%5Cfrac+%7Bln%5Ek2%7D%7Bk%21%7D%7Dx%5E%7Bk%7D%7D%3B)
8x-7x=-2-1
x=-3
0.75x-1.25x=-1
-1.5x=-1
1,5x=1
x=1/1,5
x=0.7.
1,75x+x-2x+5-7=0,75x-x+1
0,75x-0,75x-x=1+7-5.
-x=3
x=-3.
D = b*2*- 4ac = 2*2* - 4·9·(-7) = 4 + 252 = 256
Так как дискриминант больше нуля то, квадратное уравнение имеет два действительных корня:
x1 = <span>-2 - √256 / 2 * 9 = -2-16 / 18 = -18/18 = -1</span>
x2 = -2 + √256 / 2*9 = -2+16 / 18 = 14/18 = 7/9 = <span> 0.7777777777777778</span>