2x^2+2x+4=0 eching

$$2 x ^ { 2 } + 2 x + 4 = 0$$

x uchun yechish (complex solution)

$$x=\frac{-1+\sqrt{7}i}{2}\approx -0,5+1,322875656i$$

$$x=\frac{-\sqrt{7}i-1}{2}\approx -0,5-1,322875656i$$

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.

$$2x^{2}+2x+4=0$$

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

$$x=\frac{-2±\sqrt{2^{2}-4\times 2\times 4}}{2\times 2}$$

2 kvadratini chiqarish.

$$x=\frac{-2±\sqrt{4-4\times 2\times 4}}{2\times 2}$$

-4 ni 2 marotabaga ko'paytirish.

$$x=\frac{-2±\sqrt{4-8\times 4}}{2\times 2}$$

-8 ni 4 marotabaga ko'paytirish.

$$x=\frac{-2±\sqrt{4-32}}{2\times 2}$$

4 ni -32 ga qo'shish.

$$x=\frac{-2±\sqrt{-28}}{2\times 2}$$

-28 ning kvadrat ildizini chiqarish.

$$x=\frac{-2±2\sqrt{7}i}{2\times 2}$$

2 ni 2 marotabaga ko'paytirish.

$$x=\frac{-2±2\sqrt{7}i}{4}$$

x=\frac{-2±2\sqrt{7}i}{4} tenglamasini yeching, bunda ± musbat. -2 ni 2i\sqrt{7} ga qo'shish.

$$x=\frac{-2+2\sqrt{7}i}{4}$$

-2+2i\sqrt{7} ni 4 ga bo'lish.

$$x=\frac{-1+\sqrt{7}i}{2}$$

x=\frac{-2±2\sqrt{7}i}{4} tenglamasini yeching, bunda ± manfiy. -2 dan 2i\sqrt{7} ni ayirish.

$$x=\frac{-2\sqrt{7}i-2}{4}$$

-2-2i\sqrt{7} ni 4 ga bo'lish.

$$x=\frac{-\sqrt{7}i-1}{2}$$

Tenglama yechildi.

$$x=\frac{-1+\sqrt{7}i}{2} x=\frac{-\sqrt{7}i-1}{2}$$

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.

$$2x^{2}+2x+4=0$$

Tenglamaning ikkala tarafidan 4 ni ayirish.

$$2x^{2}+2x+4-4=-4$$

O‘zidan 4 ayirilsa 0 qoladi.

$$2x^{2}+2x=-4$$

Ikki tarafini 2 ga bo‘ling.

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

2 ga bo'lish 2 ga ko'paytirishni bekor qiladi.

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

2 ni 2 ga bo'lish.

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

-4 ni 2 ga bo'lish.

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

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.

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

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

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

-2 ni \frac{1}{4} ga qo'shish.

$$x^{2}+x+\frac{1}{4}=-\frac{7}{4}$$

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.

$$\left(x+\frac{1}{2}\right)^{2}=-\frac{7}{4}$$

Tenglamaning ikkala tarafining kvadrat ildizini chiqarish.

$$\sqrt{\left(x+\frac{1}{2}\right)^{2}}=\sqrt{-\frac{7}{4}}$$

Qisqartirish.

$$x+\frac{1}{2}=\frac{\sqrt{7}i}{2} x+\frac{1}{2}=-\frac{\sqrt{7}i}{2}$$

Tenglamaning ikkala tarafidan \frac{1}{2} ni ayirish.

$$x=\frac{-1+\sqrt{7}i}{2} x=\frac{-\sqrt{7}i-1}{2}$$