f(x) = 0, where
f(x) = -5x2 + 8x + 9
just use your normal methods to solve quadratic equations:
-5x^2+8x+9 = 0
I don't see any easy way to factor that, so try the quadratic formula or completing the square.
In google type :
quadratic equation online
When you see list of results click on:
Free Online Quadratic Equation Solver: Solve by Quadratic...
When page be open in rectanlgle type:
-5 x ^ 2 + 8x + 9 = 0
and click option :
solve it!
You will see solution step - by - tep
To find the value of x when f(x) = 0, we need to solve the equation -5x^2 + 8x + 9 = 0.
This is a quadratic equation, so we can use the quadratic formula to solve for x. The quadratic formula states that for an equation in the form ax^2 + bx + c = 0, the solutions for x are given by:
x = (-b ± √(b^2 - 4ac)) / (2a)
Applying this formula to our equation, we have:
a = -5, b = 8, c = 9
Plugging in the values, we get:
x = (-8 ± √(8^2 - 4(-5)(9))) / (2(-5))
Simplifying further:
x = (-8 ± √(64 + 180)) / (-10)
x = (-8 ± √244) / (-10)
x = (-8 ± 2√61) / (-10)
So the solutions for x are x = (-8 + 2√61) / (-10) and x = (-8 - 2√61) / (-10).
Now, you can calculate the values of x using a calculator or simplify further if necessary.