Question

write the equation of the line which passes through (2,1) and is perpendicular to x=-2

Answer 1

line perp to x = -2 means its slope is Undefined.. and it will never cut the y axis.
so, the equation will be:

x = 2

Answer 2

okay thanks. how do you solve these... is there a formula
?

Answer 3

@saifoo, I dont think so. x=-2 is a vertical line, perpendicular to that is a horizontal line. that will cross the y axis. the answer is y=1