x^2-x-2015=0 eching

$$x ^ { 2 } - x - 2015 = 0$$

x uchun yechish

$$x = \frac{\sqrt{8061} + 1}{2} \approx 45,391535951$$

$$x=\frac{1-\sqrt{8061}}{2}\approx -44,391535951$$

Kvadrat tenglamalaridan foydalanish qoidalari

ax^{2}+bx+c=0 shaklidagi barcha tenglamalarni kvadrat formulasi bilan yechish mumkin: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. Kvadrat formula ikki yechmni taqdim qiladi, biri ± qo'shish bo'lganda, va ikkinchisi ayiruv bo'lganda.

$$x^{2}-x-2015=0$$

Ushbu tenglama standart shaklidadir: ax^{2}+bx+c=0. Kvadrat tenglama formulasida, \frac{-b±\sqrt{b^{2}-4ac}}{2a} 1 ni a, -1 ni b va -2015 ni c bilan almashtiring.

$$x=\frac{-\left(-1\right)±\sqrt{1-4\left(-2015\right)}}{2}$$

-4 ni -2015 marotabaga ko'paytirish.

$$x=\frac{-\left(-1\right)±\sqrt{1+8060}}{2}$$

1 ni 8060 ga qo'shish.

$$x=\frac{-\left(-1\right)±\sqrt{8061}}{2}$$

-1 ning teskarisi 1 ga teng.

$$x=\frac{1±\sqrt{8061}}{2}$$

x=\frac{1±\sqrt{8061}}{2} tenglamasini yeching, bunda ± musbat. 1 ni \sqrt{8061} ga qo'shish.

$$x=\frac{\sqrt{8061}+1}{2}$$

x=\frac{1±\sqrt{8061}}{2} tenglamasini yeching, bunda ± manfiy. 1 dan \sqrt{8061} ni ayirish.

$$x=\frac{1-\sqrt{8061}}{2}$$

Tenglama yechildi.

$$x=\frac{\sqrt{8061}+1}{2} x=\frac{1-\sqrt{8061}}{2}$$

Kvadratni yakunlash bo'yicha qadamlar

Bu kabi kvadrat tenglamalarni kvadratni yakunlab yechish mumkin. Kvadratni yechish uchun tenglama avval ushbu shaklda bo'lishi shart: x^{2}+bx=c.

$$x^{2}-x-2015=0$$

2015 ni tenglamaning ikkala tarafiga qo'shish.

$$x^{2}-x-2015-\left(-2015\right)=-\left(-2015\right)$$

O‘zidan -2015 ayirilsa 0 qoladi.

$$x^{2}-x=-\left(-2015\right)$$

0 dan -2015 ni ayirish.

$$x^{2}-x=2015$$

-1 ni bo‘lish, x shartining koeffitsienti, 2 ga -\frac{1}{2} olish uchun. Keyin, -\frac{1}{2} ning kvadratini tenglamaning ikkala tarafiga qo‘shing. Ushbu qadam tenglamaning chap qismini mukammal kvadrat sifatida hosil qiladi.

$$x^{2}-x+\left(-\frac{1}{2}\right)^{2}=2015+\left(-\frac{1}{2}\right)^{2}$$

Kasrning ham suratini, ham maxrajini kvadratga ko'paytirib -\frac{1}{2} kvadratini chiqarish.

$$x^{2}-x+\frac{1}{4}=2015+\frac{1}{4}$$

2015 ni \frac{1}{4} ga qo'shish.

$$x^{2}-x+\frac{1}{4}=\frac{8061}{4}$$

x^{2}-x+\frac{1}{4} omili. Odatda, x^{2}+bx+c mukammal kvadrat bo'lsa, u doimo \left(x+\frac{b}{2}\right)^{2} omil sifatida bo'lishi mumkin.

$$\left(x-\frac{1}{2}\right)^{2}=\frac{8061}{4}$$

Tenglamaning ikkala tarafining kvadrat ildizini chiqarish.

$$\sqrt{\left(x-\frac{1}{2}\right)^{2}}=\sqrt{\frac{8061}{4}}$$

Qisqartirish.

$$x-\frac{1}{2}=\frac{\sqrt{8061}}{2} x-\frac{1}{2}=-\frac{\sqrt{8061}}{2}$$

\frac{1}{2} ni tenglamaning ikkala tarafiga qo'shish.

$$x=\frac{\sqrt{8061}+1}{2} x=\frac{1-\sqrt{8061}}{2}$$