Question

Rewrite each relation in the form y = a(x - h)^2 + k by completing the square

Answer 1

Use:$(*)\ (a\pm b)^2=a^2\pm2ab+b^2$
$a)\\y=x^2+6x-1=\underbrace{x^2+2\cdot x\cdot3+3^2}_{(*)}-3^2-1=(x+3)^2-9-1=(x+3)^2-10$


$b)\\y=x^2-6x-4=\underbrace{x^2-2\cdot x\cdot3+3^2}_{(*)}-3^2-4=(x-3)^2-9-4=(x-3)^2-13$