63.0k views
2 votes
Prove that each expression can have only positive values. 4x² - 4x + 6

User Vincentius
by
8.7k points

1 Answer

5 votes

Sure, I will guide you through this. To prove that the given expression, 4x² - 4x + 6, can only have positive values, let's proceed as follows:

1. Start by analysing the expression. Note that the expression is a quadratic equation. Quadratic equations typically have the form ax² + bx + c. Here a = 4, b = -4, and c = 6.

2. Our objective is to rewrite the expression in the form of a perfect square. The expression can be manipulated into the form 4*(x - d)² + e. We want to find the values for 'd' and 'e' that will make our equation equal to the original one.

3. Let's start with 'b', coefficient at x. It's -4, same as -2*2*d in our targeted formula. So we can find that d = 0.5.

4. Now for 'e', constant term. It's 6 in the original expression and 4*d² + e in our targeted formula. Substitute d=0.5 into 4*d² + e and simplify to find e = 5.5.

5. So, we can rewrite the original expression as 4*(x - 0.5)² + 5.5.

Now, let's consider the behavior of the perfect square term, (x - 0.5)². The minimum value this term can have is 0. This would occur when x equals 0.5.

Due to this, the smallest value our entire expression can have is when we substitute x = 0.5 into it. Doing so results in 4*0 + 5.5, which equals 5.5.

So, we see that the smallest value the original expression, 4x² - 4x + 6, can have is 5.5, which is a positive number. As such, all other values will also be positive. This means that the given expression can only have positive values.

Therefore, we have proved that the expression 4x² - 4x + 6 can only yield positive values.

User Philoniare
by
8.3k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.