Exercise
$y^2+y-1=0$
Step-by-step Solution
Learn how to solve problems step by step online. Solve the quadratic equation y^2+y+-1=0. To find the roots of a polynomial of the form ax^2+bx+c we use the quadratic formula, where in this case a=1, b=1 and c=-1. Then substitute the values of the coefficients of the equation in the quadratic formula: \displaystyle x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}. To obtain the two solutions, divide the equation in two equations, one when \pm is positive (+), and another when \pm is negative (-). Multiply -4 times -1. Multiply -4 times -1.
Solve the quadratic equation y^2+y+-1=0
Final answer to the exercise
$y=\frac{-1+\sqrt{5}}{2},\:y=\frac{-1-\sqrt{5}}{2}$