Precalculus Examples
(0,9) , (8,6)
Step 1
The midpoint formula is M=(x1+x22,y1+y22).
M=(x1+x22,y1+y22)
Step 2
Set the xM equal to the xM coordinate.
xM=x1+x22
Step 3
Solve for x1 to get x1=2xM−x2.
x1=2xM−x2
Step 4
Substitute the values for xM and x2 in x1=2xM−x2.
x1=2(0)−(8)
Step 5
Step 5.1
Simplify each term.
Step 5.1.1
Multiply 2 by 0.
x1=0−(8)
Step 5.1.2
Multiply −1 by 8.
x1=0−8
x1=0−8
Step 5.2
Subtract 8 from 0.
x1=−8
x1=−8
Step 6
Set the yM equal to the yM coordinate.
yM=y1+yM2
Step 7
Solve for y1.
y1=2yM−y2
Step 8
Substitute the values for yM and y2 in y1=2yM−y2.
y1=2(9)−(6)
Step 9
Step 9.1
Simplify each term.
Step 9.1.1
Multiply 2 by 9.
y1=18−(6)
Step 9.1.2
Multiply −1 by 6.
y1=18−6
y1=18−6
Step 9.2
Subtract 6 from 18.
y1=12
y1=12
Step 10
The start point is (−8,12).
(−8,12)