+2 votes
in Class 11 by kratos

Solve the following inequalities graphically in two dimensional plane:

(i) 3x – 6 > 0

(ii) 2x + y > 6

(iii) 3x + 4y < 12

(iv) y + 8 > 2x

(v) x - y < 2

(vi) - 3x + 2y > - 6

1 Answer

+5 votes
by kratos
 
Best answer

(i) 3x- 6 ≥ 0 ………………..(1)

Draw the graph of 3x -6 = 0 i.e., x = 2 by thick line

Put x = 0 in (1), we get - 6 > 0 which is false.

∴ Solution region does not contains the origin

The shaded region is the solution region,

(ii) 2x + y >6 …………………..(1)

Draw the graph of 2x + y = 6 by thick line. It passes through (3, 0) and (0, 6). Join these points, put x = 0 and y = 0 in (1), we get 0 + 0 > 6 which is false.

∴ Solution region does not contain the origin

(iii) 3x + 4y < 12 …………… (1)

Draw the graph of 3x + 4y = 12 by thick line. It passes through (4, 0) and (0, 3). Join these points, put x = 0 and y = 0 in (1), we get 0 + 0 ≤ 12 which is true.

∴ The solution region contains the origin

∴ The shaded region is the solution region,

(iv) y + 8 ≥2x ………… (1)

Draw the graph of y+8 = 2 by thick line It passes through (4, 0) and (0, -8) Join these points, put x = 0 and y = 0 in (1), we get 0+8≤0 which is true.

∴ The solution region contains the origin

∴ The shaded region is the solution region,

(v) x – y ≤ 2 ………… (1)

Draw the graph of x – y ≤ 2 by thick line It passes through (2, 0) and (0, -2) Join these points, put x = 0 and y = 0 in (1), we get 0 – 0 < 2 which is true.

∴ The solution region contains the origin

∴ The shaded region is the solution region.

(vi) -3x + 2y>-6 ………… (1)

Draw a graph of -3x + 2y = -6 by thick line. It passes through (2, 0) and (0, -3) Join these points, put x = 0 and y = 0 in (1), we get 0 + 0 > -6 which is true.

∴ The solution region contains the origin

∴ The shaded region is the solution region.

...