Algebra Examples
f(x)=5x2-5x+1f(x)=5x2−5x+1
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=--52(5)x=−−52(5)
Step 2.2
Remove parentheses.
x=--52(5)x=−−52(5)
Step 2.3
Simplify --52(5)−−52(5).
Step 2.3.1
Cancel the common factor of -5−5 and 55.
Step 2.3.1.1
Factor 55 out of -5−5.
x=-5⋅-12⋅5x=−5⋅−12⋅5
Step 2.3.1.2
Cancel the common factors.
Step 2.3.1.2.1
Factor 55 out of 2⋅52⋅5.
x=-5⋅-15⋅2x=−5⋅−15⋅2
Step 2.3.1.2.2
Cancel the common factor.
x=-5⋅-15⋅2
Step 2.3.1.2.3
Rewrite the expression.
x=--12
x=--12
x=--12
Step 2.3.2
Move the negative in front of the fraction.
x=--12
Step 2.3.3
Multiply --12.
Step 2.3.3.1
Multiply -1 by -1.
x=1(12)
Step 2.3.3.2
Multiply 12 by 1.
x=12
x=12
x=12
x=12
Step 3
Step 3.1
Replace the variable x with 12 in the expression.
f(12)=5(12)2-5(12)+1
Step 3.2
Simplify the result.
Step 3.2.1
Simplify each term.
Step 3.2.1.1
Apply the product rule to 12.
f(12)=5(1222)-5(12)+1
Step 3.2.1.2
One to any power is one.
f(12)=5(122)-5(12)+1
Step 3.2.1.3
Raise 2 to the power of 2.
f(12)=5(14)-5(12)+1
Step 3.2.1.4
Combine 5 and 14.
f(12)=54-5(12)+1
Step 3.2.1.5
Combine -5 and 12.
f(12)=54+-52+1
Step 3.2.1.6
Move the negative in front of the fraction.
f(12)=54-52+1
f(12)=54-52+1
Step 3.2.2
Find the common denominator.
Step 3.2.2.1
Multiply 52 by 22.
f(12)=54-(52⋅22)+1
Step 3.2.2.2
Multiply 52 by 22.
f(12)=54-5⋅22⋅2+1
Step 3.2.2.3
Write 1 as a fraction with denominator 1.
f(12)=54-5⋅22⋅2+11
Step 3.2.2.4
Multiply 11 by 44.
f(12)=54-5⋅22⋅2+11⋅44
Step 3.2.2.5
Multiply 11 by 44.
f(12)=54-5⋅22⋅2+44
Step 3.2.2.6
Multiply 2 by 2.
f(12)=54-5⋅24+44
f(12)=54-5⋅24+44
Step 3.2.3
Combine the numerators over the common denominator.
f(12)=5-5⋅2+44
Step 3.2.4
Simplify the expression.
Step 3.2.4.1
Multiply -5 by 2.
f(12)=5-10+44
Step 3.2.4.2
Subtract 10 from 5.
f(12)=-5+44
Step 3.2.4.3
Add -5 and 4.
f(12)=-14
Step 3.2.4.4
Move the negative in front of the fraction.
f(12)=-14
f(12)=-14
Step 3.2.5
The final answer is -14.
-14
-14
-14
Step 4
Use the x and y values to find where the minimum occurs.
(12,-14)
Step 5