Find the equation of the line which passes through the point (2, 2) and makes an angle of 45° with x-axis ?

Let the equation of line be

y – y1 = m(x – x1)

As it passes through (2, 2) and having slope m

= tan 45° = 1

⇒ y – 2 = 1(x – 2)

y – x = 0

or

x – y = 0