In this worksheet, we use the identity $$(x+b/2)^2 = x^2+bx+(b/2)^2 \, \, \, \, (1)$$ which is equivalent to $$x^2+bx = (x+b/2)^2 - (b/2)^2\, \, \, \, (2) $$ to complete the square. Solve each step below then click on "Show me" to check your answer. There is a graph at the bottom of the page that helps you further understand the solution to the question shown below.
Step by step solutionBelow is shown the graph of the given function (green) which is a parabola with the vertex (red point). (Change scales if necessary) Completeing the square can also be used to solve quadratic equations and Evaluate Integrals Involving Quadratics Using Completing Square. |