Precalculus Examples
f(x)=x2-4x+2f(x)=x2−4x+2
Step 1
Write f(x)=x2-4x+2f(x)=x2−4x+2 as an equation.
y=x2-4x+2y=x2−4x+2
Step 2
Step 2.1
Use the form ax2+bx+cax2+bx+c, to find the values of aa, bb, and cc.
a=1a=1
b=-4b=−4
c=2c=2
Step 2.2
Consider the vertex form of a parabola.
a(x+d)2+ea(x+d)2+e
Step 2.3
Find the value of dd using the formula d=b2ad=b2a.
Step 2.3.1
Substitute the values of aa and bb into the formula d=b2ad=b2a.
d=-42⋅1d=−42⋅1
Step 2.3.2
Cancel the common factor of -4−4 and 22.
Step 2.3.2.1
Factor 22 out of -4−4.
d=2⋅-22⋅1d=2⋅−22⋅1
Step 2.3.2.2
Cancel the common factors.
Step 2.3.2.2.1
Factor 22 out of 2⋅12⋅1.
d=2⋅-22(1)d=2⋅−22(1)
Step 2.3.2.2.2
Cancel the common factor.
d=2⋅-22⋅1
Step 2.3.2.2.3
Rewrite the expression.
d=-21
Step 2.3.2.2.4
Divide -2 by 1.
d=-2
d=-2
d=-2
d=-2
Step 2.4
Find the value of e using the formula e=c-b24a.
Step 2.4.1
Substitute the values of c, b and a into the formula e=c-b24a.
e=2-(-4)24⋅1
Step 2.4.2
Simplify the right side.
Step 2.4.2.1
Simplify each term.
Step 2.4.2.1.1
Cancel the common factor of (-4)2 and 4.
Step 2.4.2.1.1.1
Rewrite -4 as -1(4).
e=2-(-1(4))24⋅1
Step 2.4.2.1.1.2
Apply the product rule to -1(4).
e=2-(-1)2⋅424⋅1
Step 2.4.2.1.1.3
Raise -1 to the power of 2.
e=2-1⋅424⋅1
Step 2.4.2.1.1.4
Multiply 42 by 1.
e=2-424⋅1
Step 2.4.2.1.1.5
Factor 4 out of 42.
e=2-4⋅44⋅1
Step 2.4.2.1.1.6
Cancel the common factors.
Step 2.4.2.1.1.6.1
Factor 4 out of 4⋅1.
e=2-4⋅44(1)
Step 2.4.2.1.1.6.2
Cancel the common factor.
e=2-4⋅44⋅1
Step 2.4.2.1.1.6.3
Rewrite the expression.
e=2-41
Step 2.4.2.1.1.6.4
Divide 4 by 1.
e=2-1⋅4
e=2-1⋅4
e=2-1⋅4
Step 2.4.2.1.2
Multiply -1 by 4.
e=2-4
e=2-4
Step 2.4.2.2
Subtract 4 from 2.
e=-2
e=-2
e=-2
Step 2.5
Substitute the values of a, d, and e into the vertex form (x-2)2-2.
(x-2)2-2
(x-2)2-2
Step 3
Set y equal to the new right side.
y=(x-2)2-2