Question

write the quadratic function in the form y=a(x-h)^2+k
y=x^2-4x I dont know how to do this, can anyone please help me

Answer 1

well if
\[x^{2} - 4x = a(x-h)^{2} + k\]

then you can expand the RHS to

\[a(x ^{2} - 2xh + h ^{2}) + k\]

\[= ax ^{2} - 2hax + [ah ^{2} + k]\]

then, comparing different terms, ie x ^{2}, x ^{1}, and x ^{0}, solve for a, h and k. simples!