Question

If sec 0 + tan 0 = 4; then cos 0 :​

Answer 1

Answer:

secθ-tanθ = 4

Since we want cosθ at the end, let's change stuff now:

1/cosθ - sinθ/cosθ = 4

(1-sinθ) = 4cosθ

1-2sinθ+sin^2θ = 16-16sin^2θ

17sin^2θ-2sinθ-15 = 0

(15sinθ-17)(sinθ+1) = 0

sin17sin^2θ-2sinθ-15 = 15/17 or -1

So, cosθ = 8/17

The other angle is a spurious solution

Answer 2

Answer:

prefer to it!!!!!!!

Step-by-step explanation:

sec theta - tan theta=4...........................(1)

Multiplying and dividing by sec theta +tan theta

= sec - tane x sece +tan theta/sece +tan theta

= sec²0 - tan² theta /sec theta + tan theta = 4

we know that --> sec²0 - tan²0 = 1

1/sec theta + tan theta = 4

therefore,

sece + tan0 = 1/4............................…….(2)

adding equation 1 and 2.......

2 sec = 4 + 1/4

2 sec = 17/4

sec theta = 17/4*2

= 17/8

we know that

cos theta = 1/sec theta

= 1/(17/8)

= 8/17............... hope it helps