Question

If Sec∅-tan∅ = 5 find cos
∅​

Answer 1

Step-by-step explanation:

secθ−tanθ=0−(i)

we know that sec²θ−tan²θ=1

secθ+tanθ=

$\frac{1}{ \sec(θ) \tan(θ) }$

−(ii)

Adding (i) & (ii) gives

2secθ=5+

5

1

2secθ=

5

26

secθ=

5

13

cosθ=

13

5

θ=cos

−1

(

13

5

)