In the equation 2x^2-5x-6=0 I have attempted to use the quadratic formula. However, this ends up with a negative number in a square root, which obviously can't be done without some complex numbers. Is there any other way this can be done?
Check my arithmetic? You haven't helped whatsoever with that statement. Can you please explain
You're wrong in saying that it gives the square root of a negative number. Check your arithmetic.
I'm not saying the ANSWER comes to a square root of a negative I'm talking about int the quadratic formula. If THAT is were you are saying I went wrong, plase just write the correct substitutions, then I can go from here
a = 2, b = -5, c = -6, do the arithmetic.
The number under the square root sign will be positive.
Solve for x:
2 x^2-5 x-6 = 0
Divide both sides by 2:
x^2-(5 x)/2-3 = 0
Add 3 to both sides:
x^2-(5 x)/2 = 3
Add 25/16 to both sides:
x^2-(5 x)/2+25/16 = 73/16
Write the left hand side as a square:
(x-5/4)^2 = 73/16
Take the square root of both sides:
x-5/4 = sqrt(73)/4 or x-5/4 = -sqrt(73)/4
Add 5/4 to both sides:
x = 5/4+sqrt(73)/4 or x-5/4 = -sqrt(73)/4
Add 5/4 to both sides:
Answer: | x = 5/4+sqrt(73)/4 or x = 5/4-sqrt(73)/4
