Given that tanx = 1/sqr(15) and secx -4/sqr(15)

Question

find the value of sinx

Answer 1

Since the tangent is positive and the secant (or cosine) is negative, x must lie in quadrant III

construct a triangle showing an opposite side of 1 and an adjacent side of √15
by Pythagoras, the hypotenuse is 4.

so in III
sinx = -1/4