if sinA=1/3x and tanA=x/3 then find the value of x^2-1/x^2

 

1. if sinA=1/3x and tanA=x/3 then find the value of x^2-1/x^2

A) 1/5
B) 1/9
C) 1
D) 2/9

ANSWER= (B) 1/9
Explain:-

 

Explanation:

Given that, 

sinA=1/3x and tanA=x/3

We know that, 

tanA=sinA/cosA

cosA=sinA/tanA

         =1/3x/x/3

         =1/x^2

To find x^2-1/x^2

Putting the value of

 1/x^2=cosA

therefore, x^2=1/cosA

so, 

1/(cosA)-(cosA)

1-(cosA) ^2/cosA

=(sinA) ^2/cosA

=tanA*sinA

=(x/3) *1/3x

=1/9