Algebra Examples
f(x)=x2-4x+2f(x)=x2−4x+2
Step 1
The minimum of a quadratic function occurs at x=-b2ax=−b2a. If aa is positive, the minimum value of the function is f(-b2a)f(−b2a).
fminfminx=ax2+bx+cx=ax2+bx+c occurs at x=-b2ax=−b2a
Step 2
Step 2.1
Substitute in the values of aa and bb.
x=--42(1)x=−−42(1)
Step 2.2
Remove parentheses.
x=--42(1)x=−−42(1)
Step 2.3
Simplify --42(1)−−42(1).
Step 2.3.1
Cancel the common factor of -4−4 and 22.
Step 2.3.1.1
Factor 22 out of -4−4.
x=-2⋅-22⋅1x=−2⋅−22⋅1
Step 2.3.1.2
Cancel the common factors.
Step 2.3.1.2.1
Factor 22 out of 2⋅12⋅1.
x=-2⋅-22(1)x=−2⋅−22(1)
Step 2.3.1.2.2
Cancel the common factor.
x=-2⋅-22⋅1
Step 2.3.1.2.3
Rewrite the expression.
x=--21
Step 2.3.1.2.4
Divide -2 by 1.
x=--2
x=--2
x=--2
Step 2.3.2
Multiply -1 by -2.
x=2
x=2
x=2
Step 3
Step 3.1
Replace the variable x with 2 in the expression.
f(2)=(2)2-4⋅2+2
Step 3.2
Simplify the result.
Step 3.2.1
Simplify each term.
Step 3.2.1.1
Raise 2 to the power of 2.
f(2)=4-4⋅2+2
Step 3.2.1.2
Multiply -4 by 2.
f(2)=4-8+2
f(2)=4-8+2
Step 3.2.2
Simplify by adding and subtracting.
Step 3.2.2.1
Subtract 8 from 4.
f(2)=-4+2
Step 3.2.2.2
Add -4 and 2.
f(2)=-2
f(2)=-2
Step 3.2.3
The final answer is -2.
-2
-2
-2
Step 4
Use the x and y values to find where the minimum occurs.
(2,-2)
Step 5