Melengkapkan Persamaan Kuadrat

Bentuk-bentuk ( x + 2 )2, ( x -3 )2, ( x – 1 )2 disebut bentuk kuadrat sempurna. Metode ini mengubah persamaan kuadrat ax2 + bx + c = 0 dengan a ≠ 0 ke bentuk kuadrat sempurnanya, yaitu :

( x – p )2 = q → x – p = ±√q  sehingga, x = p ± √q

Berarti :

x1 = p + √q dan x2 = p – √q

Contoh Soal :

1. Diketahui persamaan kuadrat x2 – 6x + 5 = 0. Akar-akar persamaan kuadrat tersebut adalah :

Penyelesaian :

x2 – 6x + 5 = 0

( x2 + 6x + 9 ) – 4 = 0

  ↓

     ( ½ x 6 )2

( x + 3 )2 = 4

( x + 3 ) = √ 4 → x = 3 ± √4  berarti :

x1 = 3 + √4 = 5  dan x2 = 3 – √4 = 1

Jadi, akar-akar persamaan kuadrat di atas adalah 5 dan 1.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

wordpresseniyanti

belajarlah sepanjang hayat

Math Learning Blog's

Let's share your's knowledge

Ayu Ary Antari Blog's

TIDAK ADA YANG TIDAK MUNGKIN BECAUSE IMPOSSIBLE IS I AM POSSIBLE.

love peace joy with Math

diana tristiyanti's blog

niwayanseptiari

Smile! You’re at the best WordPress.com site ever

Math Is Beautiful And Fun

" Enjoy And Have Fun With Math Guys "

Putrii92

Buat Matematika Jadi Mudah

The WordPress.com Blog

The latest news on WordPress.com and the WordPress community.

%d bloggers like this: