Show that 2 - sqrt(2) is irrational

This proof can be done by contradiction.

Let us assume that 2 - √2 is rational number.

So, by the definition of rational number, we can write it as

where a & b are any integer.

⇒

Since, a and b are integers is also rational.

and therefore √2 is rational number.

This contradicts the fact that √2 is irrational number.

Hence our assumption that 2 - √2 is rational number is false.

Therefore, 2 - √2 is irrational number.

option 2 is correct.

step-by-step explanation:

we are given two inequality equation

x+y> 5 and -3x+2y< -2

first we draw the graph of both function using t-table method

equation: x+y> 5

for x=0, y=5

for x=-5, y=0

table:

x   :   0     5

y   :   5     0

test point (0,0) , 0> 5

false

equation: -3x+2y< -2

for x=0, y=-1

for x=2, y=4

table:

x   :   0     2

y   : -1       4

test point (0,0) , 0< -2

true

now we draw the graph. see the attachment for graph.

common region would be solution set.

option 2 is correct.