Question

If cos is 15/17 then what is sin

Answer 1

Since

`\cos^2(x)+\sin^2(x)=1`

we have

`\cos(x) = (15)/(17)\implies \sin(x)=\pm \sqrt{1-\left((15)/(17)\right)^2} = \pm(8)/(17)`

So, the first option is wrong. As for the tangent, we have

`\tan(\theta) = (\sin(x))/(\cos(x)) = \pm(8)/(17)\cdot (17)/(15) = \pm(8)/(15)`

So, the second option is true, assuming that
`\theta` lies in the first quadrant.

By definition, the secant is the inverse of the cosine, so the option is correct.

The cosecant is the inverse of the sine, so it should be +/- 15/8, and the option is incorrect.