Question

13th question answer is C how?

Answer 1

Given
Sec θ=3k, tan θ = 3/k

Sec^2 θ - tan ^2 θ =1

(3k)^2 - (3/k)^2=1

9k^2 - 9/k^2 =1
Divide each term with 9

k^2 - 1/k^2 = 1/9
Option C is correct

Answer 2

Hi Monica !!
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sec∅= 3k and tan∅= 3/k

sec²∅= 9k²

and Tan²∅= 9/k²

we know sec²∅- tan²∅=1

9k²-9/k²=1

9(k²-1/k²)=1

k²-1/k²=1/9

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