What is the value of the smaller zero of the function defined by 2x^2 + 9x + 7?

Question

What is the value of the smaller zero of the function defined by 2x² + 9x + 7?

Answer 1

So we can approach this problem 1 of 2 ways, we can either factor it, or use the quadratic formula.

With this quadratic, because it can be factored, I'm going to approach it that way.

We can factor the quadratic function into (2x + 7)(x + 1) and this way, the terms sum to 2x^2 + 9x + 7.

Looking at the 2 factors 2x+7 and x+1, the way to find the zeros is to set both of these expressions equal to 0.

Therefore we have:

2x+7 = 0

x+1 = 0

For the first one x = -7/2

and the second x = -1.

Because x = -7/2 is smaller, we say that x = -7/2 is our smaller zero.

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