Algebra
Calculus
Trigonometry
Matrix
Question
Find the roots
x1=4−42,x2=4+42
Alternative Form
x1≈−1.656854,x2≈9.656854
Evaluate
x2−8x−16
To find the roots of the expression,set the expression equal to 0
x2−8x−16=0
Substitute a=1,b=−8 and c=−16 into the quadratic formula x=2a−b±b2−4ac
x=28±(−8)2−4(−16)
Simplify the expression
More Steps
Evaluate
(−8)2−4(−16)
Multiply the numbers
More Steps
Evaluate
4(−16)
Multiplying or dividing an odd number of negative terms equals a negative
−4×16
Multiply the numbers
−64
(−8)2−(−64)
Rewrite the expression
82−(−64)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
82+64
Evaluate the power
64+64
Add the numbers
128
x=28±128
Simplify the radical expression
More Steps
Evaluate
128
Write the expression as a product where the root of one of the factors can be evaluated
64×2
Write the number in exponential form with the base of 8
82×2
The root of a product is equal to the product of the roots of each factor
82×2
Reduce the index of the radical and exponent with 2
82
x=28±82
Separate the equation into 2 possible cases
x=28+82x=28−82
Simplify the expression
More Steps
Evaluate
x=28+82
Divide the terms
More Steps
Evaluate
28+82
Rewrite the expression
22(4+42)
Reduce the fraction
4+42
x=4+42
x=4+42x=28−82
Simplify the expression
More Steps
Evaluate
x=28−82
Divide the terms
More Steps
Evaluate
28−82
Rewrite the expression
22(4−42)
Reduce the fraction
4−42
x=4−42
x=4+42x=4−42
Solution
x1=4−42,x2=4+42
Alternative Form
x1≈−1.656854,x2≈9.656854
Show Solution
