Question
Solve the quadratic equation
Solve using the quadratic formula
Solve by completing the square
Solve using the PQ formula
x1=1−14,x2=1+14
Alternative Form
x1≈−2.741657,x2≈4.741657
Evaluate
x2−2x−13=0
Substitute a=1,b=−2 and c=−13 into the quadratic formula x=2a−b±b2−4ac
x=22±(−2)2−4(−13)
Simplify the expression
More Steps

Evaluate
(−2)2−4(−13)
Multiply the numbers
More Steps

Evaluate
4(−13)
Multiplying or dividing an odd number of negative terms equals a negative
−4×13
Multiply the numbers
−52
(−2)2−(−52)
Rewrite the expression
22−(−52)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
22+52
Evaluate the power
4+52
Add the numbers
56
x=22±56
Simplify the radical expression
More Steps

Evaluate
56
Write the expression as a product where the root of one of the factors can be evaluated
4×14
Write the number in exponential form with the base of 2
22×14
The root of a product is equal to the product of the roots of each factor
22×14
Reduce the index of the radical and exponent with 2
214
x=22±214
Separate the equation into 2 possible cases
x=22+214x=22−214
Simplify the expression
More Steps

Evaluate
x=22+214
Divide the terms
More Steps

Evaluate
22+214
Rewrite the expression
22(1+14)
Reduce the fraction
1+14
x=1+14
x=1+14x=22−214
Simplify the expression
More Steps

Evaluate
x=22−214
Divide the terms
More Steps

Evaluate
22−214
Rewrite the expression
22(1−14)
Reduce the fraction
1−14
x=1−14
x=1+14x=1−14
Solution
x1=1−14,x2=1+14
Alternative Form
x1≈−2.741657,x2≈4.741657
Show Solution