prove that 5 - 2/7√3 is irrational number.
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Answered by
11
Suppose 5 - 2/7√3 is rational .
Let 5 - 2/7√3= r where r is a rational. =>(5-2/7√3)^2 = r2
=>25-20√3/7 +12/49 = r2
=>√3 = (r2 - 25-12/49)/ 20*7 Now , LHS = √3 is an irrational number .
RHS(r2 - 25-12/49)/ 20*7 is a rational number .
But rational number cannot be equal to
an irrational.
our supposition is wrong.
5 - 2/7√3 is irrational .
Let 5 - 2/7√3= r where r is a rational. =>(5-2/7√3)^2 = r2
=>25-20√3/7 +12/49 = r2
=>√3 = (r2 - 25-12/49)/ 20*7 Now , LHS = √3 is an irrational number .
RHS(r2 - 25-12/49)/ 20*7 is a rational number .
But rational number cannot be equal to
an irrational.
our supposition is wrong.
5 - 2/7√3 is irrational .
Answered by
5
Answer:
Step-by-step explanation:
Suppose 5 - 2/7√3 is rational .
Let 5 - 2/7√3= r where r is a rational. =>(5-2/7√3)^2 = r2
=>25-20√3/7 +12/49 = r2
=>√3 = (r2 - 25-12/49)/ 20*7 Now , LHS = √3 is an irrational number .
RHS(r2 - 25-12/49)/ 20*7 is a rational number .
But rational number cannot be equal to
an irrational.
our supposition is wrong.
5 - 2/7√3 is irrational .
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