Select the approximate values of x that are solutions to f(x) = 0, where f(x) = -4x2 + 6x + 5.

This is the same thing as finding the zeros of the function. Zeros are the same as roots or solutions.

You may notice that you cannot factor this function. That leaves completing the square or the quadratic formula to solve it. Since the coefficient of the leading term is not 1, I recommend the quadratic formula.



You can extract  from the function to get . 

Plugging into the quadratic formula, you get {}. These solutions are approximately equal to -0.6 and 2.1.