Equation to a line

Question

Give an equation to a line that is perpendicular to y=2x – 4.

Answer 1

The equation you're given (y = 2x - 4) has a slope of m = 2. (y = m x + b)

 

Slopes that are perpendicular are negative reciprocals (flip as a fraction, and switch the sign) of each other. The negative reciprocal of 2/1 is -1/2.

 

Any line that has a slope of -1/2 will be perpendicular to the line you've got.

 

y = -1/2 x

y = -1/2 x + 3

y = -1/2 x - 5

y = -1/2 x + 77

y = -1/2 x - 256

 

These are all examples of lines that satisfy your question.

Answer 2

Just give you an example: x+2y-2=0.