3+12=1/2*98r^2 eching

$$3 + 12 = \frac { 1 } { 2 } \times 98 r ^ { 2 }$$

r uchun yechish

$$r=\frac{\sqrt{15}}{7}\approx 0,553283335$$

$$r=-\frac{\sqrt{15}}{7}\approx -0,553283335$$

Kvadrat ildizini topish bo'yicha qadamlar

15 olish uchun 3 va 12'ni qo'shing.

$$15=\frac{1}{2}\times 98r^{2}$$

49 hosil qilish uchun \frac{1}{2} va 98 ni ko'paytirish.

$$15=49r^{2}$$

Tomonlarni almashtirib, barcha oʻzgaruvchi shartlar chap tomonga oʻtkazing.

$$49r^{2}=15$$

Ikki tarafini 49 ga bo‘ling.

$$r^{2}=\frac{15}{49}$$

Tenglamaning ikkala tarafining kvadrat ildizini chiqarish.

$$r=\frac{\sqrt{15}}{7} r=-\frac{\sqrt{15}}{7}$$

Kvadrat tenglamalaridan foydalanish qoidalari

15 olish uchun 3 va 12'ni qo'shing.

$$15=\frac{1}{2}\times 98r^{2}$$

49 hosil qilish uchun \frac{1}{2} va 98 ni ko'paytirish.

$$15=49r^{2}$$

Tomonlarni almashtirib, barcha oʻzgaruvchi shartlar chap tomonga oʻtkazing.

$$49r^{2}=15$$

Ikkala tarafdan 15 ni ayirish.

$$49r^{2}-15=0$$

Ushbu tenglama standart shaklidadir: ax^{2}+bx+c=0. Kvadrat tenglama formulasida, \frac{-b±\sqrt{b^{2}-4ac}}{2a} 49 ni a, 0 ni b va -15 ni c bilan almashtiring.

$$r=\frac{0±\sqrt{0^{2}-4\times 49\left(-15\right)}}{2\times 49}$$

0 kvadratini chiqarish.

$$r=\frac{0±\sqrt{-4\times 49\left(-15\right)}}{2\times 49}$$

-4 ni 49 marotabaga ko'paytirish.

$$r=\frac{0±\sqrt{-196\left(-15\right)}}{2\times 49}$$

-196 ni -15 marotabaga ko'paytirish.

$$r=\frac{0±\sqrt{2940}}{2\times 49}$$

2940 ning kvadrat ildizini chiqarish.

$$r=\frac{0±14\sqrt{15}}{2\times 49}$$

2 ni 49 marotabaga ko'paytirish.

$$r=\frac{0±14\sqrt{15}}{98}$$

r=\frac{0±14\sqrt{15}}{98} tenglamasini yeching, bunda ± musbat.

$$r=\frac{\sqrt{15}}{7}$$

r=\frac{0±14\sqrt{15}}{98} tenglamasini yeching, bunda ± manfiy.

$$r=-\frac{\sqrt{15}}{7}$$

Tenglama yechildi.

$$r=\frac{\sqrt{15}}{7} r=-\frac{\sqrt{15}}{7}$$