Q. Rewrite the function by completing the square.f(x)=x2+8x+4f(x)=(x+□)2+□
Given quadratic function: We start with the given quadratic function:f(x) = x2+8x+4To complete the square, we need to form a perfect square trinomial from the quadratic and linear terms.
Forming a perfect square trinomial: The coefficient of x is 8. To form a perfect square trinomial, we take half of the coefficient of x, which is 28=4, and then square it to get 42=16.
Adding and subtracting to maintain equality: We add and subtract this number 16 inside the function to maintain the equality:f(x)=x2+8x+16−16+4
Rewriting the function by grouping: Now we can rewrite the function by grouping the perfect square trinomial and the constants:f(x)=(x2+8x+16)−16+4
Factoring the perfect square trinomial: The expression in the parentheses is a perfect square trinomial, which can be factored into (x+4)2:f(x) = (x+4)2−16+4
Combining the constants: Finally, we combine the constants −16 and +4 to get −12: f(x)=(x+4)2−12
More problems from Solve a quadratic equation by completing the square