Final answer:
To solve for x in a quadratic equation, you can use the quadratic formula for equations of the form ax² + bx + c = 0. A graphing calculator can plot the function and find where it intersects the x-axis. Non-sensible roots are discarded in real-world applications.
Step-by-step explanation:
To find the value of x when given a function such as -2 sqrt(x) or any quadratic expression, we can employ various algebraic methods or utilize a graphing calculator. If the function is quadratic in nature, the quadratic formula can be applied, which is relevant whenever we encounter an equation of the form ax² + bx + c = 0. For instance, if we have the quadratic equation x² + 1.2 x 10⁻²x - 6.0 × 10⁻³ = 0, we can solve for x using the quadratic formula. Once the equation is accurately represented, a graphing calculator can be used to find the roots by plotting the function and identifying where it intersects the x-axis, often using the 'zero' function on the calculator.
Sometimes in practical situations, certain roots may not make sense within the context of a problem (such as a negative square root which is not possible in real-world measurements). In these cases, we discard the nonsensical root and accept the one that fits the real-world scenario, such as x = 0.00139 in a situation where x represents a concentration or pressure that cannot be negative.