Question #b6b30 Trigonometry Right Triangles Relating Trigonometric Functions 1 Answer P dilip_k Feb 21, 2017 Given sinx=1/4 and 0< x < pi/2-> x in "1st quadrant" So cosx=sqrt(1-sin^2x)=sqrt(1-1/16)=sqrt15/4 Now sin(x/2)=sqrt(1/2(1-cosx)) =sqrt(1/2(1-sqrt15/4)) =sqrt(1/8(4-sqrt15) Answer link Related questions What does it mean to find the sign of a trigonometric function and how do you find it? What are the reciprocal identities of trigonometric functions? What are the quotient identities for a trigonometric functions? What are the cofunction identities and reflection properties for trigonometric functions? What is the pythagorean identity? If sec theta = 4, how do you use the reciprocal identity to find cos theta? How do you find the domain and range of sine, cosine, and tangent? What quadrant does cot 325^@ lie in and what is the sign? How do you use use quotient identities to explain why the tangent and cotangent function have... How do you show that 1+tan^2 theta = sec ^2 theta? See all questions in Relating Trigonometric Functions Impact of this question 1557 views around the world You can reuse this answer Creative Commons License