SOLUTION: Convert the equation y(x)= -2(x-k)^2 + 4 into the standard form. Assume k is a constant whose value you do not know. I keep ending up with an extra k that doesn't fit into the

Question 320392: Convert the equation y(x)= -2(x-k)^2 + 4 into the standard form. Assume k is a constant whose value you do not know.
I keep ending up with an extra k that doesn't fit into the standard equation:
y(x)= -2(x-k)^2 + 4
= -2(x-k)(x-k)+4
= -2(x^2 -xk -xk +k)+4
= -2(x^2-2xk +k)+4
= -2x^2 +4xk +k +4 not quite standard form!
Answer by Fombitz(32388) (Show Source): You can put this solution on YOUR website!
Your derivation is correct except you made a small mistake by not distributing correctly,

Comparing to the general equation

Since is a constant, is also just a constant.

RELATED QUESTIONS
Your help is appreciated. Convert equation of the parabola y = -6x^2-6x to standard... (answered by Earlsdon)

Write an equation of a parabola whose vertex is at (-2,1) and focus is at (-3,1). I... (answered by Edwin McCravy)

Which term in the expansion of (1/(2x^3) - x^5))^8 is a constant? I know you expand it (answered by richard1234,Edwin McCravy)

Find the constant value of k so that the line having equation y =-3/4 x+k is tangent to (answered by Theo)

{{{Convert equation of the parabola y=-6^2-6x to standard form and then find the product... (answered by stanbon)

Which term in the expansion of ((1/2x^3) - x^5))^8 is a constant? I know you put it... (answered by Edwin McCravy)

Consider the quadratic equation: y=-2x^2-36x+1. Complete the square to express the... (answered by oscargut)

Write the equation of the parabola in both vertex and standard form whose vertex is... (answered by ikleyn,josgarithmetic)

How to write the equation of the line, when the 3 planes (with equations below) intersect (answered by ikleyn)