Q. Rewrite the function by completing the square.f(x)=x2+20x+40, f(x)=(x+□)2+□
Given quadratic function: We start with the given quadratic function:f(x)=x2+20x+40We want to rewrite this function in the form of (x+a)2+b.To complete the square, we need to find a value that, when added and subtracted to the x2+20x part, forms a perfect square trinomial.
Completing the square: The coefficient of x is 20. To form a perfect square trinomial, we take half of the coefficient of x, which is 220=10, and then square it to get 102=100.We add and subtract this value inside the function to complete the square.f(x)=x2+20x+100−100+40
Factoring the perfect square trinomial: Now we have the perfect square trinomial x2+20x+100 and the constants −100+40 combined.We can factor the perfect square trinomial to get (x+10)2.f(x) = (x+10)2−100+40
Simplifying the function: Combine the constants −100 and +40 to simplify the function.f(x)=(x+10)2−60Now the function is written in the completed square form.
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