1. By using Digital Differential Analyzer algorithm draw line segments from point (1,1) to (9,7).

Ans. We see that the usual equation of the line is specified by:

y = mx+c, here m = (y₁ - y₀/( x₁ - x₀)

Specified (x₀, y₀) → (1, 1) ; (x₁, y₁) → (9, 7)

⇒ m = (7-1)/(9-1) =6/8

C = y₁ - mx₁ = 7 - (6/8) *9 = 1/4

Consequently, by equation of line (y = mx + c) we contain: 

 y = (6/8)x+(1/4)

  Digital Differential Analyzer Algorithm Two case:

Case 1:   m < 1   

x_{i + 1} = x_i + 1

 y_{i + 1} = y_i + m

Case 2: m > 1   

x_{i + 1} = x_i + (1/m)

y_{i + 1} = y_i + 1

Here m < 1 so as per to Digital Differential Analyzer algorithm case 1

x_{i + 1} = xi + 1; y_{i + 1} = y_i + m

Specified (x₀, y₀) = (1, 1)

1) x₁ = x₀ + 1 = 2

y₁ = y₀ + m = 1+ (6/8) = 7/4

Place pixel (x₀, round y, colour)

That is, put on (2, 2)

Likewise, go on until (9, 7) is arrived at.