Algebra
Calculus
Trigonometry
Matrix
Question
Find the roots
x1=2−23,x2=2+23
Alternative Form
x1≈−1.464102,x2≈5.464102
Evaluate
x2−4x−8
To find the roots of the expression,set the expression equal to 0
x2−4x−8=0
Substitute a=1,b=−4 and c=−8 into the quadratic formula x=2a−b±b2−4ac
x=24±(−4)2−4(−8)
Simplify the expression
More Steps
Evaluate
(−4)2−4(−8)
Multiply the numbers
More Steps
Evaluate
4(−8)
Multiplying or dividing an odd number of negative terms equals a negative
−4×8
Multiply the numbers
−32
(−4)2−(−32)
Rewrite the expression
42−(−32)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
42+32
Evaluate the power
16+32
Add the numbers
48
x=24±48
Simplify the radical expression
More Steps
Evaluate
48
Write the expression as a product where the root of one of the factors can be evaluated
16×3
Write the number in exponential form with the base of 4
42×3
The root of a product is equal to the product of the roots of each factor
42×3
Reduce the index of the radical and exponent with 2
43
x=24±43
Separate the equation into 2 possible cases
x=24+43x=24−43
Simplify the expression
More Steps
Evaluate
x=24+43
Divide the terms
More Steps
Evaluate
24+43
Rewrite the expression
22(2+23)
Reduce the fraction
2+23
x=2+23
x=2+23x=24−43
Simplify the expression
More Steps
Evaluate
x=24−43
Divide the terms
More Steps
Evaluate
24−43
Rewrite the expression
22(2−23)
Reduce the fraction
2−23
x=2−23
x=2+23x=2−23
Solution
x1=2−23,x2=2+23
Alternative Form
x1≈−1.464102,x2≈5.464102
Show Solution
